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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Chapter 1. Status</title><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><meta name="keywords" content="ISO C++, library" /><meta name="keywords" content="ISO C++, runtime, library" /><link rel="home" href="../index.html" title="The GNU C++ Library" /><link rel="up" href="intro.html" title="Part I.  Introduction" /><link rel="prev" href="intro.html" title="Part I.  Introduction" /><link rel="next" href="license.html" title="License" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 1. Status</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="intro.html">Prev</a> </td><th width="60%" align="center">Part I. 
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</th><td width="20%" align="right"> <a accesskey="n" href="license.html">Next</a></td></tr></table><hr /></div><div class="chapter"><div class="titlepage"><div><div><h2 class="title"><a id="manual.intro.status"></a>Chapter 1. Status</h2></div></div></div><div class="toc"><p><strong>Table of Contents</strong></p><dl class="toc"><dt><span class="section"><a href="status.html#manual.intro.status.iso">Implementation Status</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#status.iso.1998">C++ 1998/2003</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.1998.status">Implementation Status</a></span></dt><dt><span class="section"><a href="status.html#iso.1998.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.2011">C++ 2011</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2011.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.2014">C++ 2014</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2014.specific">Implementation Specific Behavior</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2014.filesystemts">Filesystem TS</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="status.html#status.iso.2017">C++ 2017</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2017.specific">Implementation Specific Behavior</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.2017.par2ts">Parallelism 2 TS</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="status.html#status.iso.2020">C++ 2020</a></span></dt><dt><span class="section"><a href="status.html#status.iso.2023">C++ 2023</a></span></dt><dt><span class="section"><a href="status.html#status.iso.tr1">C++ TR1</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.tr1.specific">Implementation Specific Behavior</a></span></dt></dl></dd><dt><span class="section"><a href="status.html#status.iso.tr24733">C++ TR 24733</a></span></dt><dt><span class="section"><a href="status.html#status.iso.specfun">C++ IS 29124</a></span></dt><dd><dl><dt><span class="section"><a href="status.html#iso.specfun.specific">Implementation Specific Behavior</a></span></dt></dl></dd></dl></dd><dt><span class="section"><a href="license.html">License</a></span></dt><dd><dl><dt><span class="section"><a href="license.html#manual.intro.status.license.gpl">The Code: GPL</a></span></dt><dt><span class="section"><a href="license.html#manual.intro.status.license.fdl">The Documentation: GPL, FDL</a></span></dt></dl></dd><dt><span class="section"><a href="bugs.html">Bugs</a></span></dt><dd><dl><dt><span class="section"><a href="bugs.html#manual.intro.status.bugs.impl">Implementation Bugs</a></span></dt><dt><span class="section"><a href="bugs.html#manual.intro.status.bugs.iso">Standard Bugs</a></span></dt></dl></dd></dl></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="manual.intro.status.iso"></a>Implementation Status</h2></div></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="status.iso.1998"></a>C++ 1998/2003</h3></div></div></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="iso.1998.status"></a>Implementation Status</h4></div></div></div><p>
This status table is based on the table of contents of ISO/IEC 14882:2003.
</p><p>
This section describes the C++ support in mainline GCC, not in any
particular release.
</p><div class="table"><a id="table.cxx98_status"></a><p class="title"><strong>Table 1.1. C++ 1998/2003 Implementation Status</strong></p><div class="table-contents"><table class="table" summary="C++ 1998/2003 Implementation Status" border="1"><colgroup><col align="left" class="c1" /><col align="left" class="c2" /><col align="left" class="c3" /><col align="left" class="c4" /></colgroup><thead><tr><th align="left">Section</th><th align="left">Description</th><th align="left">Status</th><th align="left">Comments</th></tr></thead><tbody><tr><td align="left">
	<span class="emphasis"><em>18</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Language support</em></span>
      </td></tr><tr><td align="left">18.1</td><td align="left">Types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.2</td><td align="left">Implementation properties</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.2.1</td><td align="left">Numeric Limits</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">18.2.1.1</td><td align="left">Class template <code class="code">numeric_limits</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.2.1.2</td><td align="left"><code class="code">numeric_limits</code> members</td><td align="left">Y</td><td class="auto-generated"> </td></tr><tr><td align="left">18.2.1.3</td><td align="left"><code class="code">float_round_style</code></td><td align="left">Y</td><td class="auto-generated"> </td></tr><tr><td align="left">18.2.1.4</td><td align="left"><code class="code">float_denorm_style</code></td><td align="left">Y</td><td class="auto-generated"> </td></tr><tr><td align="left">18.2.1.5</td><td align="left"><code class="code">numeric_limits</code> specializations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.2.2</td><td align="left">C Library</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.3</td><td align="left">Start and termination</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.4</td><td align="left">Dynamic memory management</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.5</td><td align="left">Type identification</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">18.5.1</td><td align="left">Class type_info</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.5.2</td><td align="left">Class bad_cast</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.5.3</td><td align="left">Class bad_typeid</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.6</td><td align="left">Exception handling</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">18.6.1</td><td align="left">Class exception</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.6.2</td><td align="left">Violation exception-specifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.6.3</td><td align="left">Abnormal termination</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.6.4</td><td align="left"><code class="code">uncaught_exception</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.7</td><td align="left">Other runtime support</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>19</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Diagnostics</em></span>
      </td></tr><tr><td align="left">19.1</td><td align="left">Exception classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">19.2</td><td align="left">Assertions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">19.3</td><td align="left">Error numbers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>20</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>General utilities</em></span>
      </td></tr><tr><td align="left">20.1</td><td align="left">Requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.2</td><td align="left">Utility components</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.2.1</td><td align="left">Operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.2.2</td><td align="left"><code class="code">pair</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.3</td><td align="left">Function objects</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.3.1</td><td align="left">Base</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.3.2</td><td align="left">Arithmetic operation</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.3.3</td><td align="left">Comparisons</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.3.4</td><td align="left">Logical operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.3.5</td><td align="left">Negators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.3.6</td><td align="left">Binders</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.3.7</td><td align="left">Adaptors for pointers to functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.3.8</td><td align="left">Adaptors for pointers to members</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4</td><td align="left">Memory</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.4.1</td><td align="left">The default allocator</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.2</td><td align="left">Raw storage iterator</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.3</td><td align="left">Temporary buffers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.4</td><td align="left">Specialized algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.4.1</td><td align="left"><code class="code">uninitialized_copy</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.4.2</td><td align="left"><code class="code">uninitialized_fill</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.4.3</td><td align="left"><code class="code">uninitialized_fill_n</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.5</td><td align="left">Class template <code class="code">auto_ptr</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.6</td><td align="left">C library</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>21</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Strings</em></span>
      </td></tr><tr><td align="left">21.1</td><td align="left">Character traits</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">21.1.1</td><td align="left">Character traits requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.1.2</td><td align="left">traits typedef</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.1.3</td><td align="left"><code class="code">char_traits</code> specializations</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">21.1.3.1</td><td align="left">struct <code class="code">char_traits&lt;char&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.1.3.2</td><td align="left">struct <code class="code">char_traits&lt;wchar_t&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.2</td><td align="left">String classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.3</td><td align="left">Class template <code class="code">basic_string</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.4</td><td align="left">Null-terminated sequence utilities</td><td align="left">Y</td><td align="left">C library dependency</td></tr><tr><td align="left">
      	<span class="emphasis"><em>22</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Localization</em></span>
      </td></tr><tr><td align="left">22.1</td><td align="left">Locales</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">22.1.1</td><td align="left">Class <code class="code">locale</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.1.2</td><td align="left"><code class="code">locale</code> globals</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.1.3</td><td align="left">Convenience interfaces</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">22.1.3.1</td><td align="left">Character classification</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.1.3.2</td><td align="left">Character conversions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.2</td><td align="left">Standard locale categories</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">22.2.1</td><td align="left"><code class="code">ctype</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.2.2</td><td align="left">Numeric</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">22.2.2.1</td><td align="left"><code class="code">num_get</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.2.2.2</td><td align="left"><code class="code">num_put</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.2.3</td><td align="left"><code class="code">num_punct</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.2.4</td><td align="left"><code class="code">collate</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.2.5</td><td align="left">Time</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">22.2.5.1</td><td align="left"><code class="code">time_get</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.2.5.2</td><td align="left"><code class="code">time_get_byname</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.2.5.3</td><td align="left"><code class="code">time_put</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.2.5.3</td><td align="left"><code class="code">time_put_byname</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.2.6</td><td align="left">Monetary</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">22.2.6.1</td><td align="left"><code class="code">money_get</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.2.6.2</td><td align="left"><code class="code">money_put</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.2.6.3</td><td align="left"><code class="code">money_punct</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.2.6.4</td><td align="left"><code class="code">money_punct_byname</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.2.7</td><td align="left"><code class="code">messages</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.2.8</td><td align="left">Program-defined facets</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.3</td><td align="left">C Library Locales</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>23</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Containers</em></span>
      </td></tr><tr><td align="left">23.1</td><td align="left">Container requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.2</td><td align="left">Sequence containers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.2.1</td><td align="left">Class template <code class="code">deque</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.2.2</td><td align="left">Class template <code class="code">list</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.2.3</td><td align="left">Adaptors</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.2.3.1</td><td align="left">Class template <code class="code">queue</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.2.3.2</td><td align="left">Class template <code class="code">priority_queue</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.2.3.3</td><td align="left">Class template <code class="code">stack</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.2.4</td><td align="left">Class template <code class="code">vector</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.2.5</td><td align="left">Class <code class="code">vector&lt;bool&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.3</td><td align="left">Associative containers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.3.1</td><td align="left">Class template <code class="code">map</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.3.2</td><td align="left">Class template <code class="code">multimap</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.3.3</td><td align="left">Class template <code class="code">set</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.3.4</td><td align="left">Class template <code class="code">multiset</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>24</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Iterators</em></span>
      </td></tr><tr><td align="left">24.1</td><td align="left">Requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.2</td><td align="left">Header <code class="code">&lt;iterator&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.3</td><td align="left">Iterator primitives</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.4</td><td align="left">Predefined iterators and Iterator adaptors</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">24.4.1</td><td align="left">Reverse iterators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.4.2</td><td align="left">Insert iterators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.5</td><td align="left">Stream iterators</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">24.5.1</td><td align="left">Class template <code class="code">istream_iterator</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.5.2</td><td align="left">Class template <code class="code">ostream_iterator</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.5.3</td><td align="left">Class template <code class="code">istreambuf_iterator</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.5.4</td><td align="left">Class template <code class="code">ostreambuf_iterator</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>25</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Algorithms</em></span>
      </td></tr><tr><td align="left">25.1</td><td align="left">Non-modifying sequence operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">25.2</td><td align="left">Mutating sequence operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">25.3</td><td align="left">Sorting and related operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">25.4</td><td align="left">C library algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
      <span class="emphasis"><em>26</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Numerics</em></span>
      </td></tr><tr><td align="left">26.1</td><td align="left">Numeric type requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.2</td><td align="left">Complex numbers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.3</td><td align="left">Numeric arrays</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.3.1</td><td align="left">Header <code class="code">&lt;valarray&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.3.2</td><td align="left">Class template <code class="code">valarray</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.3.3</td><td align="left"><code class="code">valarray</code> non-member operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.3.4</td><td align="left">Class <code class="code">slice</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.3.5</td><td align="left">Class template <code class="code">slice_array</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.3.6</td><td align="left">Class <code class="code">gslice</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.3.7</td><td align="left">Class template <code class="code">gslice_array</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.3.8</td><td align="left">Class template <code class="code">mask_array</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.3.9</td><td align="left">Class template <code class="code">indirect_array</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.4</td><td align="left">Generalized numeric operations</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.4.1</td><td align="left"><code class="code">accumulate</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.4.2</td><td align="left"><code class="code">inner_product</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.4.3</td><td align="left"><code class="code">partial_sum</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.4.4</td><td align="left"><code class="code">adjacent_difference</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.4.5</td><td align="left">iota</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5</td><td align="left">C Library</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>27</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Input/output</em></span>
      </td></tr><tr><td align="left">27.1</td><td align="left">Requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.2</td><td align="left">Forward declarations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.3</td><td align="left">Standard iostream objects</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.3.1</td><td align="left">Narrow stream objects</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.3.2</td><td align="left">Wide stream objects</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.4</td><td align="left">Iostreams base classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.5</td><td align="left">Stream buffers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.6</td><td align="left">Formatting and manipulators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.7</td><td align="left">String-based streams</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.8</td><td align="left">File-based streams</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
      	<span class="emphasis"><em>Appendix D</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Compatibility features</em></span>
      </td></tr><tr><td align="left">D.1</td><td align="left">Increment operator with bool operand</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">D.2</td><td align="left"><code class="code">static</code> keyword</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">D.3</td><td align="left">Access declarations</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">D.4</td><td align="left">Implicit conversion from const strings</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">D.5</td><td align="left">C standard library headers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">D.6</td><td align="left">Old iostreams members</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">D.7</td><td align="left">char* streams</td><td align="left"> </td><td align="left"> </td></tr></tbody></table></div></div><br class="table-break" /></div><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="iso.1998.specific"></a>Implementation Specific Behavior</h4></div></div></div><p>
     The ISO standard defines the following phrase:
   </p><div class="blockquote"><blockquote class="blockquote"><div class="variablelist"><dl class="variablelist"><dt><span class="term">
	 <code class="code">[1.3.5] implementation-defined behavior</code>
       </span></dt><dd><p>
	 Behavior, for a well-formed program construct and correct data, that
	 depends on the implementation <span class="emphasis"><em>and that each implementation
	 shall document</em></span>.
	 </p></dd></dl></div></blockquote></div><p>
     We do so here, for the C++ library only.  Behavior of the
     compiler, linker, runtime loader, and other elements of "the
     implementation" are documented elsewhere.  Everything listed
     in Annex B, Implementation Qualities, are also part of the
     compiler, not the library.
   </p><p>
     For each entry, we give the section number of the standard, when
     applicable.  This list is probably incomplet and inkorrekt.
   </p><p>
     <span class="emphasis"><em>[1.9]/11 #3</em></span> If <code class="code">isatty(3)</code> is true, then
      interactive stream support is implied.
   </p><p>
     <span class="emphasis"><em>[17.4.4.5]</em></span> Non-reentrant functions are probably best
      discussed in the various sections on multithreading (see above).
   </p><p><span class="emphasis"><em>[18.1]/4</em></span> The type of <code class="code">NULL</code> is described
      under <a class="link" href="support.html#std.support.types.null" title="NULL">Support</a>.
   </p><p><span class="emphasis"><em>[18.3]/8</em></span> Even though it's listed in the library
      sections, libstdc++ has zero control over what the cleanup code hands
      back to the runtime loader.  Talk to the compiler people.  :-)
   </p><p><span class="emphasis"><em>[18.4.2.1]/5</em></span> (bad_alloc),
      <span class="emphasis"><em>[18.5.2]/5</em></span> (bad_cast),
      <span class="emphasis"><em>[18.5.3]/5</em></span> (bad_typeid),
      <span class="emphasis"><em>[18.6.1]/8</em></span> (exception),
      <span class="emphasis"><em>[18.6.2.1]/5</em></span> (bad_exception):  The <code class="code">what()</code>
      member function of class <code class="code">std::exception</code>, and these other
      classes publicly derived from it, returns the name of the
      class, e.g. <code class="literal">"std::bad_alloc"</code>.
   </p><p><span class="emphasis"><em>[18.5.1]/7</em></span> The return value of
      <code class="code">std::type_info::name()</code> is the mangled type name.
      You will need to call <code class="code">c++filt</code> and pass the names as
      command-line parameters to demangle them, or call a
      <a class="link" href="ext_demangling.html" title="Chapter 28. Demangling">runtime demangler function</a>.
   </p><p><span class="emphasis"><em>[20.1.5]/5</em></span> <span class="emphasis"><em>"Implementors are encouraged to
      supply libraries that can accept allocators that encapsulate more
      general memory models and that support non-equal instances.  In such
      implementations, any requirements imposed on allocators by containers
      beyond those requirements that appear in Table 32, and the semantics
      of containers and algorithms when allocator instances compare
      non-equal, are implementation-defined."</em></span>  There is experimental
      support for non-equal allocators in the standard containers in C++98
      mode. There are no additional requirements on allocators. It is undefined
      behaviour to swap two containers if their allocators are not equal.
   </p><p><span class="emphasis"><em>[21.1.3.1]/3,4</em></span>,
      <span class="emphasis"><em>[21.1.3.2]/2</em></span>,
      <span class="emphasis"><em>[21.3]/6 basic_string::iterator, basic_string::const_iterator</em></span>,
      <span class="emphasis"><em>[23.*]'s foo::iterator</em></span>,
      <span class="emphasis"><em>[27.*]'s foo::*_type</em></span>,
      <span class="emphasis"><em>others...</em></span>
      Nope, these types are called implementation-defined because you
      shouldn't be taking advantage of their underlying types.  Listing them
      here would defeat the purpose.  :-)
   </p><p><span class="emphasis"><em>[21.1.3.1]/5</em></span> I don't really know about
      the <span class="type">mbstate_t</span> stuff... see
      the <a class="link" href="facets.html#std.localization.facet.codecvt" title="codecvt"><code class="code">codecvt</code>
      notes</a> for what does exist.
   </p><p><span class="emphasis"><em>[22.*]</em></span> Anything and everything we have on locale
      implementation will be described under
      <a class="link" href="localization.html#std.localization.locales.locale" title="locale">Localization</a>.
   </p><p><span class="emphasis"><em>[23.*]</em></span> All of the containers in this clause
     define <span class="type">size_type</span> as <span class="type">std::size_t</span> and
     <span class="type">difference_type</span> as <span class="type">std::ptrdiff_t</span>.
   </p><p><span class="emphasis"><em>[26.2.8]/9</em></span> I have no idea what
      <code class="code">complex&lt;T&gt;</code>'s <code class="code">pow(0,0)</code> returns.
   </p><p><span class="emphasis"><em>[27.4.2.4]/2</em></span> Calling
      <code class="code">std::ios_base::sync_with_stdio</code> after I/O has already been
      performed on the standard stream objects will
      flush the buffers, and 
      destroy and recreate the underlying buffer instances.  Whether or not
      the previously-written I/O is destroyed in this process depends mostly
      on the <code class="code">--enable-libio</code> choice:  for stdio, if the written
      data is already in the stdio buffer, the data may be completely safe!
   </p><p><span class="emphasis"><em>[27.6.1.1.2]</em></span>,
      <span class="emphasis"><em>[27.6.2.3]</em></span> The I/O sentry ctor and dtor can perform
      additional work than the minimum required.  We are not currently taking
      advantage of this yet.
   </p><p><span class="emphasis"><em>[27.7.1.3]/16</em></span>,
      <span class="emphasis"><em>[27.8.1.4]/10</em></span>
      The effects of <code class="code">pubsetbuf/setbuf</code> are described in the
      <a class="link" href="io.html" title="Chapter 13.  Input and Output">Input and Output</a> chapter.
   </p><p><span class="emphasis"><em>[27.8.1.4]/16</em></span> Calling <code class="code">fstream::sync</code> when
      a get area exists will... whatever <code class="code">fflush()</code> does, I think.
   </p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="status.iso.2011"></a>C++ 2011</h3></div></div></div><p>
<a id="status.iso.200x"></a> 
This table is based on the table of contents of ISO/IEC
JTC1 SC22 WG21 Doc No: N3290 Date: 2011-04-11
Final Draft International Standard, Standard for Programming Language C++
</p><p>
In this implementation the <code class="literal">-std=gnu++11</code> or
<code class="literal">-std=c++11</code> flag must be used to enable language
and library
features. See <a class="link" href="using.html#manual.intro.using.flags" title="Command Options">dialect</a>
options. The pre-defined symbol
<code class="constant">__cplusplus</code> is used to check for the
presence of the required flag.
GCC 5.1 was the first release with non-experimental C++11 support,
so the API and ABI of features added in C++11 is only stable
since that release.
</p><p>
This status table is based on the table of contents of ISO/IEC 14882:2011.
</p><p>
This section describes the C++11 support in mainline GCC, not in any
particular release.
</p><div class="table"><a id="table.cxx11_status"></a><p class="title"><strong>Table 1.2. C++ 2011 Implementation Status</strong></p><div class="table-contents"><table class="table" summary="C++ 2011 Implementation Status" border="1"><colgroup><col align="left" class="c1" /><col align="left" class="c2" /><col align="left" class="c3" /><col align="left" class="c4" /></colgroup><thead><tr><th align="left">Section</th><th align="left">Description</th><th align="left">Status</th><th align="left">Comments</th></tr></thead><tbody><tr><td align="left">
	<span class="emphasis"><em>18</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Language support</em></span>
      </td></tr><tr><td align="left">18.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">18.2</td><td align="left">Types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.3</td><td align="left">Implementation properties</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">18.3.2</td><td align="left">Numeric Limits</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">18.3.2.3</td><td align="left">Class template <code class="code">numeric_limits</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.3.2.4</td><td align="left"><code class="code">numeric_limits</code> members</td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">18.3.2.5</td><td align="left"><code class="code">float_round_style</code></td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">18.3.2.6</td><td align="left"><code class="code">float_denorm_style</code></td><td align="left">N</td><td align="left"> </td></tr><tr><td align="left">18.3.2.7</td><td align="left"><code class="code">numeric_limits</code> specializations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.3.3</td><td align="left">C Library</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.4</td><td align="left">Integer types</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">18.4.1</td><td align="left">Header <code class="code">&lt;cstdint&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">18.5</td><td align="left">Start and termination</td><td align="left">Partial</td><td align="left">C library dependency for quick_exit, at_quick_exit</td></tr><tr><td align="left">18.6</td><td align="left">Dynamic memory management</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.7</td><td align="left">Type identification</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">18.7.1</td><td align="left">Class type_info</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.7.2</td><td align="left">Class bad_cast</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.7.3</td><td align="left">Class bad_typeid</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.8</td><td align="left">Exception handling</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">18.8.1</td><td align="left">Class exception</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.8.2</td><td align="left">Class bad_exception</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.8.3</td><td align="left">Abnormal termination</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.8.4</td><td align="left"><code class="code">uncaught_exception</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.8.5</td><td align="left">Exception Propagation</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.8.6</td><td align="left"><code class="code">nested_exception</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.9</td><td align="left">Initializer lists</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">18.9.1</td><td align="left">Initializer list constructors</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.9.2</td><td align="left">Initializer list access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.9.3</td><td align="left">Initializer list range access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.10</td><td align="left">Other runtime support</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>19</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Diagnostics</em></span>
      </td></tr><tr><td align="left">19.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">19.2</td><td align="left">Exception classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">19.3</td><td align="left">Assertions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">19.4</td><td align="left">Error numbers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">19.5</td><td align="left">System error support</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">19.5.1</td><td align="left">Class <code class="code">error_category</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">19.5.2</td><td align="left">Class <code class="code">error_code</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">19.5.3</td><td align="left">Class <code class="code">error_condition</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">19.5.4</td><td align="left">Comparison operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">19.5.5</td><td align="left">Class <code class="code">system_error</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>20</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>General utilities</em></span>
      </td></tr><tr><td align="left">20.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.2</td><td align="left">Utility components</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.2.1</td><td align="left">Operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.2.2</td><td align="left">swap</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.2.3</td><td align="left">forward/move helpers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.2.4</td><td align="left">Function template <code class="code">declval</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.3</td><td align="left">Pairs</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.3.1</td><td align="left">In general</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.3.2</td><td align="left">Class template <code class="code">pair</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.3.3</td><td align="left">Specialized algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.3.4</td><td align="left">Tuple-like access to <code class="code">pair</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.3.5</td><td align="left">Piecewise construction</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4</td><td align="left">Tuples</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.4.1</td><td align="left">In general</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.4.2</td><td align="left">Class template <code class="code">tuple</code></td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.4.2.1</td><td align="left">Construction</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.2.2</td><td align="left">Assignment</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.2.3</td><td align="left">Swap</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.2.4</td><td align="left">Tuple creation functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.2.5</td><td align="left">Tuple helper classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.2.6</td><td align="left">Element access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.2.7</td><td align="left">Relational operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.2.8</td><td align="left">Tuple traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.2.9</td><td align="left">Tuple specialized algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.5</td><td align="left">Class template <code class="code">bitset</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.5.1</td><td align="left"><code class="code">bitset</code> constructors</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.5.2</td><td align="left"><code class="code">bitset</code> members</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.5.3</td><td align="left"><code class="code">bitset</code> hash support</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.5.4</td><td align="left"><code class="code">bitset</code> operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6</td><td align="left">Memory</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.6.1</td><td align="left">In general</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.6.2</td><td align="left">Header <code class="code">&lt;memory&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.6.3</td><td align="left">Pointer traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.4</td><td align="left">Pointer safety</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.5</td><td align="left">Align</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.6</td><td align="left">Allocator argument tag</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.7</td><td align="left"><code class="code">uses_allocator</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.8</td><td align="left">Allocator traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.9</td><td align="left">The default allocator</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.10</td><td align="left">Raw storage iterator</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.11</td><td align="left">Temporary buffers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.12</td><td align="left">Specialized algorithms</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.6.12.1</td><td align="left"><code class="code">addressof</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.12.2</td><td align="left"><code class="code">uninitialized_copy</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.12.3</td><td align="left"><code class="code">uninitialized_fill</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.12.4</td><td align="left"><code class="code">uninitialized_fill_n</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.13</td><td align="left">C library</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.7</td><td align="left">Smart pointers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.7.1</td><td align="left">Class template <code class="code">unique_ptr</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.7.2</td><td align="left">Shared-ownership pointers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.7.2.1</td><td align="left">Class <code class="code">bad_weak_ptr</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.7.2.2</td><td align="left">Class template <code class="code">shared_ptr</code></td><td align="left">Y</td><td align="left">
	  Uses code from
	  <a class="link" href="http://www.boost.org/libs/smart_ptr/shared_ptr.htm" target="_top">boost::shared_ptr</a>.
      </td></tr><tr><td align="left">20.7.2.3</td><td align="left">Class template <code class="code">weak_ptr</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.7.2.4</td><td align="left">Class template <code class="code">enable_shared_from_this</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.7.2.5</td><td align="left"><code class="code">shared_ptr</code> atomic access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.7.2.6</td><td align="left">Smart pointer hash support</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8</td><td align="left">Function objects</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.8.1</td><td align="left">Definitions</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.8.2</td><td align="left">Requirements</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.8.3</td><td align="left">Class template <code class="code">reference_wrapper</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.4</td><td align="left">Arithmetic operation</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.5</td><td align="left">Comparisons</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.6</td><td align="left">Logical operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.7</td><td align="left">Bitwise operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.8</td><td align="left">Negators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.9</td><td align="left">Function template <code class="code">bind</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.10</td><td align="left">Function template <code class="code">mem_fn</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.11</td><td align="left">Polymorphic function wrappers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.8.11.1</td><td align="left">Class <code class="code">bad_function_call</code></td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">20.8.11.2</td><td align="left">Class template <code class="code">function</code></td><td align="left">Partial</td><td align="left">Missing allocator support</td></tr><tr><td align="left">20.8.12</td><td align="left">Class template <code class="code">hash</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9</td><td align="left">Metaprogramming and type traits</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.9.1</td><td align="left">Requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.2</td><td align="left">Header <code class="code">&lt;type_traits&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.9.3</td><td align="left">Helper classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.4</td><td align="left">Unary Type Traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.4.1</td><td align="left">Primary type categories</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.4.2</td><td align="left">Composite type traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.4.3</td><td align="left">Type properties</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.5</td><td align="left">Type property queries</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.6</td><td align="left">Relationships between types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7</td><td align="left">Transformations between types</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.9.7.1</td><td align="left">Const-volatile modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7.2</td><td align="left">Reference modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7.3</td><td align="left">Sign modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7.4</td><td align="left">Array modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7.5</td><td align="left">Pointer modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7.6</td><td align="left">Other transformations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.10</td><td align="left">Compile-time rational arithmetic</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.10.1</td><td align="left">In general</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.10.2</td><td align="left">Header <code class="code">&lt;ratio&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.10.3</td><td align="left">Class template <code class="code">ratio</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.10.4</td><td align="left">Arithmetic on <code class="code">ratio</code>s</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.10.5</td><td align="left">Comparison of <code class="code">ratio</code>s</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.10.6</td><td align="left">SI types for <code class="code">ratio</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11</td><td align="left">Time utilities</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.11.3</td><td align="left">Clock requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.4</td><td align="left">Time-related traits</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.11.4.1</td><td align="left"><code class="code">treat_as_floating_point</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.4.2</td><td align="left"><code class="code">duration_values</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.4.3</td><td align="left">Specializations of <code class="code">common_type</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.5</td><td align="left">Class template <code class="code">duration</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.6</td><td align="left">Class template <code class="code">time_point</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.7</td><td align="left">Clocks</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.11.7.1</td><td align="left">Class <code class="code">system_clock</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.7.2</td><td align="left">Class <code class="code">steady_clock</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.7.3</td><td align="left">Class <code class="code">high_resolution_clock</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.8</td><td align="left">Date and time functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12</td><td align="left">Scoped allocator adaptor</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12.1</td><td align="left">Header <code class="code">&lt;scoped_allocator&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.12.2</td><td align="left">Scoped allocator adaptor member types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12.3</td><td align="left">Scoped allocator adaptor constructors</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12.4</td><td align="left">Scoped allocator adaptor members</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12.5</td><td align="left">Scoped allocator operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.13</td><td align="left">Class <code class="code">type_index</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>21</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Strings</em></span>
      </td></tr><tr><td align="left">21.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.2</td><td align="left">Character traits</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">21.2.1</td><td align="left">Character traits requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.2.2</td><td align="left">traits typedefs</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.2.3</td><td align="left"><code class="code">char_traits</code> specializations</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">21.2.3.1</td><td align="left">struct <code class="code">char_traits&lt;char&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.2.3.2</td><td align="left">struct <code class="code">char_traits&lt;char16_t&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.2.3.3</td><td align="left">struct <code class="code">char_traits&lt;char32_t&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.2.3.4</td><td align="left">struct <code class="code">char_traits&lt;wchar_t&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.3</td><td align="left">String classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.4</td><td align="left">Class template <code class="code">basic_string</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.5</td><td align="left">Numeric Conversions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.6</td><td align="left">Hash support</td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">21.7</td><td align="left">Null-terminated sequence utilities</td><td align="left">Partial</td><td align="left">C library dependency. </td></tr><tr><td align="left">
      	<span class="emphasis"><em>22</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Localization</em></span>
      </td></tr><tr><td align="left">22.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.2</td><td align="left">Header <code class="code">&lt;locale&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.3</td><td align="left">Locales</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">22.3.1</td><td align="left">Class <code class="code">locale</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.3.2</td><td align="left"><code class="code">locale</code> globals</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.3.3</td><td align="left">Convenience interfaces</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">22.3.3.1</td><td align="left">Character classification</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.3.3.2</td><td align="left">Conversions</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">22.3.3.2.1</td><td align="left">Character conversions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.3.3.2.2</td><td align="left"><code class="code">string</code> conversions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.3.3.2.3</td><td align="left">Buffer conversions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.4</td><td align="left">Standard <code class="code">locale</code> categories</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">22.4.1</td><td align="left">The <code class="code">ctype</code> category</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.4.2</td><td align="left">The numeric category</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">22.4.2.1</td><td align="left"><code class="code">num_get</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.4.2.2</td><td align="left"><code class="code">num_put</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.4.3</td><td align="left">The numeric punctuation facet</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.4.4</td><td align="left">The collate category</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.4.5</td><td align="left">The time category</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">22.4.5.1</td><td align="left">Class template <code class="code">time_get</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.4.5.2</td><td align="left">Class template <code class="code">time_get_byname</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.4.5.3</td><td align="left">Class template <code class="code">time_put</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.4.5.3</td><td align="left">Class template <code class="code">time_put_byname</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.4.6</td><td align="left">The monetary category</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">22.4.6.1</td><td align="left">Class template <code class="code">money_get</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.4.6.2</td><td align="left">Class template <code class="code">money_put</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.4.6.3</td><td align="left">Class template <code class="code">money_punct</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.4.6.4</td><td align="left">Class template <code class="code">money_punct_byname</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.4.7</td><td align="left">The message retrieval category</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.4.8</td><td align="left">Program-defined facets</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.5</td><td align="left">Standard code conversion facets</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.6</td><td align="left">C Library Locales</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>23</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Containers</em></span>
      </td></tr><tr><td align="left">23.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.2</td><td align="left">Container requirements</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.2.1</td><td align="left">General container requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.2.2</td><td align="left">Container data races</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.2.3</td><td align="left">Sequence containers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.2.4</td><td align="left">Associative containers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.2.5</td><td align="left">Unordered associative containers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.3</td><td align="left">Sequence containers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.3.2</td><td align="left">Class template <code class="code">array</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.3.3</td><td align="left">Class template <code class="code">deque</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.3.4</td><td align="left">Class template <code class="code">forward_list</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.3.5</td><td align="left">Class template <code class="code">list</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.3.6</td><td align="left">Class template <code class="code">vector</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.3.7</td><td align="left">Class <code class="code">vector&lt;bool&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.4</td><td align="left">Associative containers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.4.4</td><td align="left">Class template <code class="code">map</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.4.5</td><td align="left">Class template <code class="code">multimap</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.4.6</td><td align="left">Class template <code class="code">set</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.4.7</td><td align="left">Class template <code class="code">multiset</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.5</td><td align="left">Unordered associative containers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.5.4</td><td align="left">Class template <code class="code">unordered_map</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.5.5</td><td align="left">Class template <code class="code">unordered_multimap</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.5.6</td><td align="left">Class template <code class="code">unordered_set</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.5.7</td><td align="left">Class template <code class="code">unordered_multiset</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.6</td><td align="left">Container adaptors</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.6.1</td><td align="left">Class template <code class="code">queue</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.6.2</td><td align="left">Class template <code class="code">priority_queue</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.6.3</td><td align="left">Class template <code class="code">stack</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>24</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Iterators</em></span>
      </td></tr><tr><td align="left">24.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.2</td><td align="left">Iterator requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.3</td><td align="left">Header <code class="code">&lt;iterator&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.4</td><td align="left">Iterator primitives</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.5</td><td align="left">Iterator adaptors</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">24.5.1</td><td align="left">Reverse iterators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.5.2</td><td align="left">Insert iterators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.5.3</td><td align="left">Move iterators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.6</td><td align="left">Stream iterators</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">24.6.1</td><td align="left">Class template <code class="code">istream_iterator</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.6.2</td><td align="left">Class template <code class="code">ostream_iterator</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.6.3</td><td align="left">Class template <code class="code">istreambuf_iterator</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.6.4</td><td align="left">Class template <code class="code">ostreambuf_iterator</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.6.5</td><td align="left">range access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>25</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Algorithms</em></span>
      </td></tr><tr><td align="left">25.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">25.2</td><td align="left">Non-modifying sequence operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">25.3</td><td align="left">Mutating sequence operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">25.4</td><td align="left">Sorting and related operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">25.5</td><td align="left">C library algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
      <span class="emphasis"><em>26</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Numerics</em></span>
      </td></tr><tr><td align="left">26.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.2</td><td align="left">Numeric type requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.3</td><td align="left">The floating-point environment</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.4</td><td align="left">Complex numbers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5</td><td align="left">Random number generation</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.5.1</td><td align="left">Requirements</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.5.2</td><td align="left">Header <code class="code">&lt;random&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.5.3</td><td align="left">Random number engine class templates</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.5.3.1</td><td align="left">Class template <code class="code">linear_congruential_engine</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.3.2</td><td align="left">Class template <code class="code">mersenne_twister_engine</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.3.3</td><td align="left">Class template <code class="code">subtract_with_carry_engine</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.4</td><td align="left">Random number engine adaptor class templates</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.5.4.2</td><td align="left">Class template <code class="code">discard_block_engine</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.4.3</td><td align="left">Class template <code class="code">independent_bits_engine</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.4.4</td><td align="left">Class template <code class="code">shuffle_order_engine</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.5</td><td align="left">Engines and engine adaptors with predefined parameters</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.6</td><td align="left">Class <code class="code">random_device</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.7</td><td align="left">Utilities</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.5.7.1</td><td align="left">Class <code class="code">seed_seq</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.7.2</td><td align="left">Function template <code class="code">generate_canonical</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8</td><td align="left">Random number distribution class templates</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.5.8.2</td><td align="left">Uniform distributions</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.5.8.2.1</td><td align="left">Class template <code class="code">uniform_int_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.2.2</td><td align="left">Class template <code class="code">uniform_real_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.3</td><td align="left">Bernoulli distributions</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.5.8.3.1</td><td align="left">Class <code class="code">bernoulli_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.3.2</td><td align="left">Class template <code class="code">binomial_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.3.3</td><td align="left">Class template <code class="code">geometric_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.3.4</td><td align="left">Class template <code class="code">negative_binomial_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.4</td><td align="left">Poisson distributions</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.5.8.4.1</td><td align="left">Class template <code class="code">poisson_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.4.2</td><td align="left">Class template <code class="code">exponential_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.4.3</td><td align="left">Class template <code class="code">gamma_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.4.4</td><td align="left">Class template <code class="code">weibull_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.4.5</td><td align="left">Class template <code class="code">extreme_value_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.5</td><td align="left">Normal distributions</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.5.8.5.1</td><td align="left">Class template <code class="code">normal_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.5.2</td><td align="left">Class template <code class="code">lognormal_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.5.3</td><td align="left">Class template <code class="code">chi_squared_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.5.4</td><td align="left">Class template <code class="code">cauchy_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.5.5</td><td align="left">Class template <code class="code">fisher_f_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.5.6</td><td align="left">Class template <code class="code">student_t_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.6</td><td align="left">Sampling distributions</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.5.8.6.1</td><td align="left">Class template <code class="code">discrete_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.6.2</td><td align="left">Class template <code class="code">piecewise_constant_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5.8.6.3</td><td align="left">Class template <code class="code">piecewise_linear_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.6</td><td align="left">Numeric arrays</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.6.1</td><td align="left">Header <code class="code">&lt;valarray&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.6.2</td><td align="left">Class template <code class="code">valarray</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.6.3</td><td align="left"><code class="code">valarray</code> non-member operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.6.4</td><td align="left">Class <code class="code">slice</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.6.5</td><td align="left">Class template <code class="code">slice_array</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.6.6</td><td align="left">The <code class="code">gslice</code> class</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.6.7</td><td align="left">Class template <code class="code">gslice_array</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.6.8</td><td align="left">Class template <code class="code">mask_array</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.6.9</td><td align="left">Class template <code class="code">indirect_array</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.6.10</td><td align="left"><code class="code">valarray</code> range access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.7</td><td align="left">Generalized numeric operations</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.7.1</td><td align="left">Header <code class="code">&lt;numeric&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.7.2</td><td align="left">Accumulate&gt;</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.7.3</td><td align="left">Inner product</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.7.4</td><td align="left">Partial sum</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.7.5</td><td align="left">Adjacent difference</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.7.6</td><td align="left">Iota</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.8</td><td align="left">C Library</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>27</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Input/output library</em></span>
      </td></tr><tr><td align="left">27.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.2</td><td align="left">Iostreams requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.2.1</td><td align="left">Imbue Limitations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.2.2</td><td align="left">Positioning Type Limitations</td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">27.2.3</td><td align="left">Thread safety</td><td align="left">Partial</td><td align="left"> </td></tr><tr><td align="left">27.3</td><td align="left">Forward declarations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.4</td><td align="left">Standard iostream objects</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.4.1</td><td align="left">Overview</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.4.2</td><td align="left">Narrow stream objects</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.4.3</td><td align="left">Wide stream objects</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.5</td><td align="left">Iostreams base classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.6</td><td align="left">Stream buffers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.7</td><td align="left">Formatting and manipulators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.8</td><td align="left">String-based streams</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.9</td><td align="left">File-based streams</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>28</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Regular expressions</em></span>
      </td></tr><tr><td align="left">28.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.2</td><td align="left">Definitions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.3</td><td align="left">Requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.4</td><td align="left">Header <code class="code">&lt;regex&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.5</td><td align="left">Namespace <code class="code">std::regex_constants</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.6</td><td align="left">Class <code class="code">regex_error</code></td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">28.7</td><td align="left">Class template <code class="code">regex_traits</code></td><td align="left">Partial</td><td align="left"><code class="code">transform_primary</code> is not correctly implemented</td></tr><tr><td align="left">28.8</td><td align="left">Class template <code class="code">basic_regex</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.9</td><td align="left">Class template <code class="code">sub_match</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.10</td><td align="left">Class template <code class="code">match_results</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.11</td><td align="left">Regular expression algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.12</td><td align="left">Regular expression Iterators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.13</td><td align="left">Modified ECMAScript regular expression grammar</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>29</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Atomic operations</em></span>
      </td></tr><tr><td align="left">29.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.2</td><td align="left">Header <code class="code">&lt;atomic&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.3</td><td align="left">Order and consistency</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.4</td><td align="left">Lock-free property</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.5</td><td align="left">Atomic types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.6</td><td align="left">Operations on atomic types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.7</td><td align="left">Flag Type and operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.8</td><td align="left">Fences</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>30</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Thread support</em></span>
      </td></tr><tr><td align="left">30.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.2</td><td align="left">Requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.3</td><td align="left">Threads</td><td align="left"> </td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">30.3.1</td><td align="left">Class <code class="code">thread</code></td><td align="left">Partial</td><td align="left"><code class="code">thread::id</code> comparisons not well-defined</td></tr><tr><td align="left">30.3.2</td><td align="left">Namespace <code class="code">this_thread</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4</td><td align="left">Mutual exclusion</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.4.1</td><td align="left">Mutex requirements</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.4.1.1</td><td align="left">In general</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.4.1.2</td><td align="left">Mutex types</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.4.1.2.1</td><td align="left">Class <code class="code">mutex</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4.1.2.2</td><td align="left">Class <code class="code">recursive_mutex</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4.1.3</td><td align="left">Timed mutex types</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.4.1.3.1</td><td align="left">Class <code class="code">timed_mutex</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4.1.3.2</td><td align="left">Class <code class="code">recursive_timed_mutex</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4.2</td><td align="left">Locks</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.4.2.1</td><td align="left">Class template <code class="code">lock_guard</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4.2.2</td><td align="left">Class template <code class="code">unique_lock</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4.3</td><td align="left">Generic locking algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4.4</td><td align="left">Call once</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.4.4.1</td><td align="left">Struct <code class="code">once_flag</code></td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">30.4.4.2</td><td align="left">Function <code class="code">call_once</code></td><td align="left">Y</td><td align="left">Exception support is broken on non-Linux targets.
	See <a class="link" href="https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66146" target="_top">PR
	66146</a>.
      </td></tr><tr><td align="left">30.5</td><td align="left">Condition variables</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.5.1</td><td align="left">Class <code class="code">condition_variable</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.5.2</td><td align="left">Class <code class="code">condition_variable_any</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.6</td><td align="left">Futures</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.6.1</td><td align="left">Overview</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.6.2</td><td align="left">Error handling</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.6.3</td><td align="left">Class <code class="code">future_error</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.6.4</td><td align="left">Shared state</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.6.5</td><td align="left">Class template <code class="code">promise</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.6.6</td><td align="left">Class template <code class="code">future</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.6.7</td><td align="left">Class template <code class="code">shared_future</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.6.8</td><td align="left">Function template <code class="code">async</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.6.9</td><td align="left">Class template <code class="code">packaged_task</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
      	<span class="emphasis"><em>Appendix D</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Compatibility features</em></span>
      </td></tr><tr><td align="left">D.1</td><td align="left">Increment operator with <code class="code">bool</code> operand</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">D.2</td><td align="left"><code class="code">register</code> keyword</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">D.3</td><td align="left">Implicit declaration of copy functions</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">D.4</td><td align="left">Dynamic exception specifications</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">D.5</td><td align="left">C standard library headers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.6</td><td align="left">Old iostreams members</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.7</td><td align="left"><code class="code">char*</code> streams</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.8</td><td align="left">Function objects</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.9</td><td align="left">Binders</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.10</td><td align="left"><code class="code">auto_ptr</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.11</td><td align="left">Violating exception-specifications</td><td align="left">Y</td><td align="left"> </td></tr></tbody></table></div></div><br class="table-break" /><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="iso.2011.specific"></a>Implementation Specific Behavior</h4></div></div></div><p>For behaviour which is also specified by the 1998 and 2003 standards,
      see <a class="link" href="status.html#iso.1998.specific" title="Implementation Specific Behavior">C++ 1998/2003 Implementation
      Specific Behavior</a>. This section only documents behaviour which
      is new in the 2011 standard.
   </p><p>
      <span class="emphasis"><em>17.6.5.12 [res.on.exception.handling]</em></span>
      There are no implementation-defined exception classes, only standard
      exception classes (or classes derived from them) will be thrown.
   </p><p>
      <span class="emphasis"><em>17.6.5.14 [value.error.codes]</em></span>
      The <code class="classname">error_category</code> for errors originating outside
      the OS, and the possible error code values for each error category,
      should be documented here.
   </p><p>
      <span class="emphasis"><em>18.6.2.2 [new.badlength]</em></span>
      <code class="function">what()</code> returns
      <code class="literal">"std::bad_array_new_length"</code>.
   </p><p>
      <span class="emphasis"><em>20.6.9.1 [allocator.member]/5</em></span>
      Over-aligned types are not supported by
      <code class="classname">std::allocator</code>.
   </p><p>
      <span class="emphasis"><em>20.7.2.2.1 [util.smartptr.shared.const]</em></span>
      When a <code class="classname">shared_ptr</code> constructor fails
      <code class="classname">bad_alloc</code> (or types derived from it) will
      be thrown, or when an allocator is passed to the constructor then any
      exceptions thrown by the allocator.
   </p><p>
      <span class="emphasis"><em>20.7.2.0 [util.smartptr.weakptr]</em></span>
      <code class="code">what()</code> returns <code class="literal">"bad_weak_ptr"</code>.
   </p><p>
      <span class="emphasis"><em>20.8.9.1.3 [func.bind.place]/1</em></span> There are 29
      placeholders defined and the placeholder types are
      <code class="literal">CopyAssignable</code>.
   </p><p>
      <span class="emphasis"><em>20.11.7.1 [time.clock.system]/3, /4</em></span>
      Time point values are truncated to <code class="code">time_t</code> values.
      There is no loss of precision for conversions in the other direction.
   </p><p>
      <span class="emphasis"><em>20.15.7 [meta.trans]/2</em></span>
      <code class="classname">aligned_storage</code> does not support extended
      alignment.
   </p><p>
      <span class="emphasis"><em>21.2.3.2 [char.traits.specializations.char16_t]</em></span>,
      <span class="emphasis"><em>21.2.3.3 [char.traits.specializations.char32_t]</em></span>
      The types <code class="classname">u16streampos</code> and
      <code class="classname">u32streampos</code> are both synonyms for
      <code class="classname">fpos&lt;mbstate_t&gt;</code>.
      The function <code class="function">eof</code> returns <code class="code">int_type(-1)</code>.
      <code class="function">char_traits&lt;char16_t&gt;::to_int_type</code> will
      transform the "noncharacter" U+FFFF to U+FFFD (REPLACEMENT CHARACTER).
      This is done to ensure that <code class="function">to_int_type</code> never
      returns the same value as <code class="function">eof</code>, which is U+FFFF.
   </p><p>
      <span class="emphasis"><em>22.3.1 [locale]</em></span>
      There is one global locale for the whole program, not per-thread.
   </p><p>
      <span class="emphasis"><em>22.4.5.1.2 [locale.time.get.virtuals]</em></span>,
      <span class="emphasis"><em>22.4.5.3.2 [locale.time.put.virtuals]</em></span>
      Additional supported formats should be documented here.
   </p><p>
      <span class="emphasis"><em> 22.4.7.1.2 [locale.messages.virtuals]</em></span>
      The mapping should be documented here.
   </p><p>
      <span class="emphasis"><em>23.3.2.1 [array.overview]</em></span>
      <code class="classname">array&lt;T, N&gt;::iterator</code> is <code class="code">T*</code> and
      <code class="classname">array&lt;T, N&gt;::const_iterator</code> is
      <code class="code">const T*</code>.
   </p><p>
      <span class="emphasis"><em>23.5.4.2 [unord.map.cnstr]</em></span>,
      <span class="emphasis"><em>23.5.5.2 [unord.multimap.cnstr]</em></span>,
      <span class="emphasis"><em>23.5.6.2 [unord.set.cnstr]</em></span>,
      <span class="emphasis"><em>23.5.7.2 [unord.multiset.cnstr]</em></span>
      The default minimal bucket count is 0 for the default constructors, range
      constructors and initializer-list constructors.
   </p><p>
      <span class="emphasis"><em>25.3.12 [alg.random.shuffle]</em></span>
      The two-argument overload of <code class="function">random_shuffle</code>
      uses <code class="function">rand</code> as the source of randomness.
   </p><p>
      <span class="emphasis"><em>26.5.5 [rand.predef]</em></span>
      The type <code class="classname">default_random_engine</code> is a synonym for
      <code class="classname">minstd_rand0</code>.
   </p><p>
      <span class="emphasis"><em> 26.5.6 [rand.device] </em></span>
      The <code class="code">token</code> parameter of the
      <code class="classname">random_device</code> constructor can be used to select
      a specific source of random bytes. The valid token values are shown
      in the list below.
      The default constructor uses the token <code class="literal">"default"</code>.
      </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">"default"</code></span></dt><dd>
          Select the first available source from the other entries below.
          This is the only token that is always valid.
        </dd><dt><span class="term"><code class="literal">"rand_s"</code></span></dt><dd>
          Use the MSVCRT <code class="function">rand_s</code> function.
          This token is only valid for mingw-w64 targets.
        </dd><dt><span class="term"><code class="literal">"rdseed"</code>, </span><span class="term"><code class="literal">"rdrand"</code> or <code class="literal">"rdrnd"</code></span></dt><dd>
          Use the IA-32 <code class="literal">RDSEED</code> or <code class="literal">RDRAND</code>
          instruction to read from an on-chip hardware random number generator.
          These tokens are only valid for x86 and x86_64 targets when both
          the assembler and CPU support the corresponding instruction.
        </dd><dt><span class="term"><code class="literal">"darn"</code></span></dt><dd>
          Use the Power ISA-3.0 <code class="literal">DARN</code>
          ("Deliver A Random Number")
          instruction to read from an on-chip hardware random number generator.
          This token is only valid for 64-bit powerpc targets when both
          the assembler and CPU support the corresponding instruction.
        </dd><dt><span class="term"><code class="literal">"hw"</code>, </span><span class="term"><code class="literal">"hardware"</code></span></dt><dd>
          Use any available CPU
          instruction to read from an on-chip hardware random number generator.
          This is equivalent to trying each of the following and using the
          first that is supported:
          <code class="literal">"rdseed"</code><code class="literal">"rdrand"</code><code class="literal">"darn"</code></dd><dt><span class="term"><code class="literal">"arc4random"</code>, </span><span class="term"><code class="literal">"getentropy"</code></span></dt><dd>
          Use the named C library function, if available on the target.
        </dd><dt><span class="term"><code class="literal">"/dev/urandom"</code>, </span><span class="term"><code class="literal">"/dev/random"</code></span></dt><dd>
          Use the named character special file to read random bytes from.
          These tokens are only valid when the device files are present
          and readable by the current user.
        </dd><dt><span class="term"><code class="literal">"mt19937"</code>, </span><span class="term">seed value</span></dt><dd>
          When no source of nondeterministic random numbers is available a
          <code class="classname">mersenne_twister_engine</code> will be used.
          An integer seed value can be used as the token and will be converted
          to an <code class="code">unsigned long</code> using <code class="function">strtoul</code>.
          These tokens are only valid when no other source of random bytes
          is available.
        </dd></dl></div><p>
      An exception of type <code class="classname">runtime_error</code> will be
      thrown if a <code class="classname">random_device</code> object is constructed
      with an invalid token, or if it cannot open or read from the source
      of random bytes.
   </p><p>
      <span class="emphasis"><em>26.5.8.1 [rand.dist.general]</em></span>
      The algorithms used by the distributions should be documented here.
   </p><p>
      <span class="emphasis"><em>26.8 [c.math]</em></span> Whether the
      <code class="function">rand</code> function introduces data races depends on
      the C library as the function is not provided by libstdc++.
   </p><p>
      <span class="emphasis"><em>27.8.2.1 [stringbuf.cons]</em></span>
      Whether the sequence pointers are copied by the
      <code class="classname">basic_stringbuf</code> move constructor should be
      documented here.
   </p><p>
      <span class="emphasis"><em>27.9.1.2 [filebuf.cons]</em></span>
      Whether the sequence pointers are copied by the
      <code class="classname">basic_filebuf</code> move constructor should be
      documented here.
   </p><p>
      <span class="emphasis"><em>28.5.1 [re.synopt]</em></span>,
      <span class="emphasis"><em> 28.5.2 [re.matchflag] </em></span>,
      <span class="emphasis"><em> 28.5.3 [re.err] </em></span>
      <code class="code">syntax_option_type</code>, <code class="code">match_flag_type</code>
      and <code class="code">error_type</code> are unscoped enumeration types.
   </p><p>
      <span class="emphasis"><em>28.7 [re.traits]</em></span>
      The <code class="literal">blank</code> character class corresponds to the
      <code class="code">ctype_base::blank</code> mask.
   </p><p>
      <span class="emphasis"><em>29.4 [atomics.lockfree]</em></span>
      The values of the <code class="code">ATOMIC_xxx_LOCK_FREE</code> macros depend on
      the target and cannot be listed here.
   </p><p>
      <span class="emphasis"><em>30.2.3 [thread.req.native]/1</em></span>
      <code class="classname">native_handle_type</code> and
      <code class="methodname">native_handle</code> are provided. The handle types
      are defined in terms of the Gthreads abstraction layer, although this
      is subject to change at any time. Any use of
      <code class="classname">native_handle</code> is inherently non-portable and
      not guaranteed to work between major releases of GCC.
      </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="classname">thread</code></span></dt><dd>
            The native handle type is a typedef for <code class="code">__gthread_t</code>
            i.e. <code class="code">pthread_t</code> when GCC is configured with the
            <code class="literal">posix</code> thread model.
            The value of the native handle is undefined for a thread
            which is not joinable.
         </dd><dt><span class="term"><code class="classname">mutex</code>, </span><span class="term"><code class="classname">timed_mutex</code></span></dt><dd>
            The native handle type is <code class="code">__gthread_mutex_t*</code> i.e.
            <code class="code">pthread_mutex_t*</code> for the <code class="literal">posix</code>
            thread model.
         </dd><dt><span class="term"><code class="classname">recursive_mutex</code>, </span><span class="term"><code class="classname">recursive_timed_mutex</code></span></dt><dd>
            The native handle type is <code class="code">__gthread_recursive_mutex_t*</code>
            i.e. <code class="code">pthread_mutex_t*</code> for the <code class="literal">posix</code>
            thread model.
         </dd><dt><span class="term"><code class="classname">condition_variable</code></span></dt><dd>
            The native handle type is <code class="code">__gthread_cond_t*</code> i.e.
            <code class="code">pthread_cond_t*</code> for the <code class="literal">posix</code>
            thread model.
         </dd></dl></div><p>
   </p><p>
      <span class="emphasis"><em>30.6.1 [futures.overview]/2</em></span>
      <code class="code">launch</code> is a scoped enumeration type with
      overloaded operators to support bitmask operations. There are no
      additional bitmask elements defined.
   </p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="status.iso.2014"></a>C++ 2014</h3></div></div></div><p>
In this implementation the <code class="literal">-std=gnu++14</code> or
<code class="literal">-std=c++14</code> flag must be used to enable language
and library
features. See <a class="link" href="using.html#manual.intro.using.flags" title="Command Options">dialect</a>
options. The pre-defined symbol
<code class="constant">__cplusplus</code> is used to check for the
presence of the required flag.
GCC 6.1 was the first release with non-experimental C++14 support,
so the API and ABI of features added in C++14 is only stable
since that release.
</p><p>
This status table is based on the table of contents of ISO/IEC 14882:2014.
Some subclauses are not shown in the table where the content is unchanged
since C++11 and the implementation is complete.
</p><p>
This section describes the C++14 and library TS support in mainline GCC,
not in any particular release.
</p><div class="table"><a id="table.cxx14_status"></a><p class="title"><strong>Table 1.3. C++ 2014 Implementation Status</strong></p><div class="table-contents"><table class="table" summary="C++ 2014 Implementation Status" border="1"><colgroup><col align="left" class="c1" /><col align="left" class="c2" /><col align="left" class="c3" /><col align="left" class="c4" /></colgroup><thead><tr><th align="left">Section</th><th align="left">Description</th><th align="left">Status</th><th align="left">Comments</th></tr></thead><tbody><tr><td align="left">
	<span class="emphasis"><em>18</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Language support</em></span>
      </td></tr><tr><td align="left">18.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">18.2</td><td align="left">Types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.3</td><td align="left">Implementation properties</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">18.3.2</td><td align="left">Numeric Limits</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">18.3.2.3</td><td align="left">Class template <code class="code">numeric_limits</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.3.2.4</td><td align="left"><code class="code">numeric_limits</code> members</td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">18.3.2.5</td><td align="left"><code class="code">float_round_style</code></td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">18.3.2.6</td><td align="left"><code class="code">float_denorm_style</code></td><td align="left">N</td><td align="left"> </td></tr><tr><td align="left">18.3.2.7</td><td align="left"><code class="code">numeric_limits</code> specializations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.3.3</td><td align="left">C Library</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.4</td><td align="left">Integer types</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">18.4.1</td><td align="left">Header <code class="code">&lt;cstdint&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">18.5</td><td align="left">Start and termination</td><td align="left">Partial</td><td align="left">C library dependency for quick_exit, at_quick_exit</td></tr><tr><td align="left">18.6</td><td align="left">Dynamic memory management</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.7</td><td align="left">Type identification</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">18.7.1</td><td align="left">Class type_info</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.7.2</td><td align="left">Class bad_cast</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.7.3</td><td align="left">Class bad_typeid</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.8</td><td align="left">Exception handling</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">18.8.1</td><td align="left">Class exception</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.8.2</td><td align="left">Class bad_exception</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.8.3</td><td align="left">Abnormal termination</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.8.4</td><td align="left"><code class="code">uncaught_exception</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.8.5</td><td align="left">Exception Propagation</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.8.6</td><td align="left"><code class="code">nested_exception</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.9</td><td align="left">Initializer lists</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">18.9.1</td><td align="left">Initializer list constructors</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.9.2</td><td align="left">Initializer list access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.9.3</td><td align="left">Initializer list range access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">18.10</td><td align="left">Other runtime support</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>19</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Diagnostics</em></span>
      </td></tr><tr><td align="left">19.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">19.2</td><td align="left">Exception classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">19.3</td><td align="left">Assertions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">19.4</td><td align="left">Error numbers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">19.5</td><td align="left">System error support</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">19.5.1</td><td align="left">Class <code class="code">error_category</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">19.5.2</td><td align="left">Class <code class="code">error_code</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">19.5.3</td><td align="left">Class <code class="code">error_condition</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">19.5.4</td><td align="left">Comparison operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">19.5.5</td><td align="left">Class <code class="code">system_error</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>20</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>General utilities</em></span>
      </td></tr><tr><td align="left">20.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.2</td><td align="left">Utility components</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.2.1</td><td align="left">Operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.2.2</td><td align="left">swap</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.2.3</td><td align="left">exchange</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.2.4</td><td align="left">forward/move helpers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.2.5</td><td align="left">Function template <code class="code">declval</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.3</td><td align="left">Pairs</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4</td><td align="left">Tuples</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.5</td><td align="left">Compile-time integer sequences</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.5.2</td><td align="left">Class template <code class="code">integer_sequence</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.5.3</td><td align="left">Alias template <code class="code">make_integer_sequence</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6</td><td align="left">Class template <code class="code">bitset</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.7</td><td align="left">Memory</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8</td><td align="left">Smart pointers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.8.1</td><td align="left">Class template <code class="code">unique_ptr</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.1.1</td><td align="left">Default deleters</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.1.2</td><td align="left"><code class="code">unique_ptr</code> for single objects</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.1.3</td><td align="left"><code class="code">unique_ptr</code> for array objects with a runtime length</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.1.4</td><td align="left"><code class="code">unique_ptr</code> creation</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.1.5</td><td align="left"><code class="code">unique_ptr</code> specialized algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.2</td><td align="left">Shared-ownership pointers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.8.2.1</td><td align="left">Class <code class="code">bad_weak_ptr</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.2.2</td><td align="left">Class template <code class="code">shared_ptr</code></td><td align="left">Y</td><td align="left">
	  Uses code from
	  <a class="link" href="http://www.boost.org/libs/smart_ptr/shared_ptr.htm" target="_top">boost::shared_ptr</a>.
      </td></tr><tr><td align="left">20.8.2.3</td><td align="left">Class template <code class="code">weak_ptr</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.2.4</td><td align="left">Class template <code class="code">owner_less</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.2.5</td><td align="left">Class template <code class="code">enable_shared_from_this</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.2.6</td><td align="left"><code class="code">shared_ptr</code> atomic access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.2.7</td><td align="left">Smart pointer hash support</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9</td><td align="left">Function objects</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.9.1</td><td align="left">Definitions</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.9.2</td><td align="left">Requirements</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.9.3</td><td align="left">Class template <code class="code">reference_wrapper</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.4</td><td align="left">Arithmetic operation</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.5</td><td align="left">Comparisons</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.6</td><td align="left">Logical operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7</td><td align="left">Bitwise operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.8</td><td align="left">Negators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.9</td><td align="left">Function object binders</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.10</td><td align="left">Function template <code class="code">mem_fn</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.11</td><td align="left">Polymorphic function wrappers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.9.11.1</td><td align="left">Class <code class="code">bad_function_call</code></td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">20.9.11.2</td><td align="left">Class template <code class="code">function</code></td><td align="left">Partial</td><td align="left">Missing allocator support</td></tr><tr><td align="left">20.9.12</td><td align="left">Class template <code class="code">hash</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.10</td><td align="left">Metaprogramming and type traits</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.10.1</td><td align="left">Requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.10.2</td><td align="left">Header <code class="code">&lt;type_traits&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.10.3</td><td align="left">Helper classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.10.4</td><td align="left">Unary Type Traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.10.5</td><td align="left">Type property queries</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.10.6</td><td align="left">Relationships between types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.10.7</td><td align="left">Transformations between types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11</td><td align="left">Compile-time rational arithmetic</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12</td><td align="left">Time utilities</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.12.3</td><td align="left">Clock requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12.4</td><td align="left">Time-related traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12.5</td><td align="left">Class template <code class="code">duration</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12.5.8</td><td align="left">Suffixes for duration literals</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12.6</td><td align="left">Class template <code class="code">time_point</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12.7</td><td align="left">Clocks</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12.8</td><td align="left">Date and time functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.13</td><td align="left">Scoped allocator adaptor</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.14</td><td align="left">Class <code class="code">type_index</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>21</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Strings</em></span>
      </td></tr><tr><td align="left">21.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.2</td><td align="left">Character traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.3</td><td align="left">String classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.4</td><td align="left">Class template <code class="code">basic_string</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.5</td><td align="left">Numeric Conversions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.6</td><td align="left">Hash support</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.7</td><td align="left">Suffixes for <code class="code">basic_string</code> literals</td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">21.7</td><td align="left">Null-terminated sequence utilities</td><td align="left">Partial</td><td align="left">C library dependency. </td></tr><tr><td align="left">
	<span class="emphasis"><em>22</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Localization</em></span>
      </td></tr><tr><td align="left">22.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.2</td><td align="left">Header <code class="code">&lt;locale&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.3</td><td align="left">Locales</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.4</td><td align="left">Standard <code class="code">locale</code> categories</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.5</td><td align="left">Standard code conversion facets</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.6</td><td align="left">C Library Locales</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>23</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Containers</em></span>
      </td></tr><tr><td align="left">23.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.2</td><td align="left">Container requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.3</td><td align="left">Sequence containers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.4</td><td align="left">Associative containers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.5</td><td align="left">Unordered associative containers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.6</td><td align="left">Container adaptors</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>24</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Iterators</em></span>
      </td></tr><tr><td align="left">24.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.2</td><td align="left">Iterator requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.3</td><td align="left">Header <code class="code">&lt;iterator&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.4</td><td align="left">Iterator primitives</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.5</td><td align="left">Iterator adaptors</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.6</td><td align="left">Stream iterators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.7</td><td align="left">range access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>25</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Algorithms</em></span>
      </td></tr><tr><td align="left">25.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">25.2</td><td align="left">Non-modifying sequence operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">25.3</td><td align="left">Mutating sequence operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">25.4</td><td align="left">Sorting and related operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">25.5</td><td align="left">C library algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
      <span class="emphasis"><em>26</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Numerics</em></span>
      </td></tr><tr><td align="left">26.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.2</td><td align="left">Numeric type requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.3</td><td align="left">The floating-point environment</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.4</td><td align="left">Complex numbers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.4.10</td><td align="left">Suffixes for complex number literals</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5</td><td align="left">Random number generation</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.6</td><td align="left">Numeric arrays</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.7</td><td align="left">Generalized numeric operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.8</td><td align="left">C Library</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>27</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Input/output library</em></span>
      </td></tr><tr><td align="left">27.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.2</td><td align="left">Iostreams requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.2.1</td><td align="left">Imbue Limitations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.2.2</td><td align="left">Positioning Type Limitations</td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">27.2.3</td><td align="left">Thread safety</td><td align="left">Partial</td><td align="left"> </td></tr><tr><td align="left">27.3</td><td align="left">Forward declarations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.4</td><td align="left">Standard iostream objects</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.5</td><td align="left">Iostreams base classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.6</td><td align="left">Stream buffers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.7</td><td align="left">Formatting and manipulators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.7.6</td><td align="left">Quoted manipulators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.8</td><td align="left">String-based streams</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.9</td><td align="left">File-based streams</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>28</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Regular expressions</em></span>
      </td></tr><tr><td align="left">28.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.2</td><td align="left">Definitions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.3</td><td align="left">Requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.4</td><td align="left">Header <code class="code">&lt;regex&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.5</td><td align="left">Namespace <code class="code">std::regex_constants</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.6</td><td align="left">Class <code class="code">regex_error</code></td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">28.7</td><td align="left">Class template <code class="code">regex_traits</code></td><td align="left">Partial</td><td align="left"><code class="code">transform_primary</code> is not correctly implemented</td></tr><tr><td align="left">28.8</td><td align="left">Class template <code class="code">basic_regex</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.9</td><td align="left">Class template <code class="code">sub_match</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.10</td><td align="left">Class template <code class="code">match_results</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.11</td><td align="left">Regular expression algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.12</td><td align="left">Regular expression Iterators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.13</td><td align="left">Modified ECMAScript regular expression grammar</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>29</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Atomic operations</em></span>
      </td></tr><tr><td align="left">29.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.2</td><td align="left">Header <code class="code">&lt;atomic&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.3</td><td align="left">Order and consistency</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.4</td><td align="left">Lock-free property</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.5</td><td align="left">Atomic types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.6</td><td align="left">Operations on atomic types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.7</td><td align="left">Flag Type and operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.8</td><td align="left">Fences</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>30</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Thread support</em></span>
      </td></tr><tr><td align="left">30.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.2</td><td align="left">Requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.3</td><td align="left">Threads</td><td align="left"> </td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">30.3.1</td><td align="left">Class <code class="code">thread</code></td><td align="left">Partial</td><td align="left"><code class="code">thread::id</code> comparisons not well-defined</td></tr><tr><td align="left">30.3.2</td><td align="left">Namespace <code class="code">this_thread</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4</td><td align="left">Mutual exclusion</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.4.1</td><td align="left">Mutex requirements</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.4.1.1</td><td align="left">In general</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.4.1.2</td><td align="left">Mutex types</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.4.1.2.1</td><td align="left">Class <code class="code">mutex</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4.1.2.2</td><td align="left">Class <code class="code">recursive_mutex</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4.1.3</td><td align="left">Timed mutex types</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.4.1.3.1</td><td align="left">Class <code class="code">timed_mutex</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4.1.3.2</td><td align="left">Class <code class="code">recursive_timed_mutex</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4.1.4</td><td align="left">Shared timed mutex types</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.4.1.4.1</td><td align="left">Class <code class="code">shared_timed_mutex</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4.2</td><td align="left">Locks</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.4.2.1</td><td align="left">Class template <code class="code">lock_guard</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4.2.2</td><td align="left">Class template <code class="code">unique_lock</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4.2.3</td><td align="left">Class template <code class="code">shared_lock</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4.3</td><td align="left">Generic locking algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4.4</td><td align="left">Call once</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.4.4.1</td><td align="left">Struct <code class="code">once_flag</code></td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">30.4.4.2</td><td align="left">Function <code class="code">call_once</code></td><td align="left">Broken</td><td align="left">Exception support is broken on non-Linux targets.
	See <a class="link" href="https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66146" target="_top">PR
	66146</a>.
      </td></tr><tr><td align="left">30.5</td><td align="left">Condition variables</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.5.1</td><td align="left">Class <code class="code">condition_variable</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.5.2</td><td align="left">Class <code class="code">condition_variable_any</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.6</td><td align="left">Futures</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.6.1</td><td align="left">Overview</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">30.6.2</td><td align="left">Error handling</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.6.3</td><td align="left">Class <code class="code">future_error</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.6.4</td><td align="left">Shared state</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.6.5</td><td align="left">Class template <code class="code">promise</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.6.6</td><td align="left">Class template <code class="code">future</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.6.7</td><td align="left">Class template <code class="code">shared_future</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.6.8</td><td align="left">Function template <code class="code">async</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.6.9</td><td align="left">Class template <code class="code">packaged_task</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>Appendix D</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Compatibility features</em></span>
      </td></tr><tr><td align="left">D.1</td><td align="left">Increment operator with <code class="code">bool</code> operand</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">D.2</td><td align="left"><code class="code">register</code> keyword</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">D.3</td><td align="left">Implicit declaration of copy functions</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">D.4</td><td align="left">Dynamic exception specifications</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">D.5</td><td align="left">C standard library headers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.6</td><td align="left">Old iostreams members</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.7</td><td align="left"><code class="code">char*</code> streams</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.8</td><td align="left">Function objects</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.9</td><td align="left">Binders</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.10</td><td align="left"><code class="code">auto_ptr</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.11</td><td align="left">Violating exception-specifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.12</td><td align="left">Random shuffle</td><td align="left">Y</td><td align="left"> </td></tr></tbody></table></div></div><br class="table-break" /><div class="table"><a id="table.ts_status"></a><p class="title"><strong>Table 1.4. C++ Technical Specifications Implementation Status</strong></p><div class="table-contents"><table class="table" summary="C++ Technical Specifications Implementation Status" border="1"><colgroup><col align="left" class="c1" /><col align="left" class="c2" /><col align="left" class="c3" /><col align="left" class="c4" /></colgroup><thead><tr><th align="left">Paper</th><th align="left">Title</th><th align="left">Status</th><th align="left">Comments</th></tr></thead><tbody><tr bgcolor="#C8B0B0"><td align="left">
	<a class="link" href="https://www.open-std.org/JTC1/sc22/WG21/docs/papers/2013/n3662.html" target="_top">
	  N3662
	</a>
      </td><td align="left">C++ Dynamic Arrays</td><td align="left">N</td><td align="left">Array Extensions TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/JTC1/SC22/WG21/docs/papers/2013/n3793.html" target="_top">
	  N3793
	</a>
      </td><td align="left">A proposal to add a utility class to represent optional objects</td><td align="left">Y</td><td align="left">Library Fundamentals TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/JTC1/SC22/WG21/docs/papers/2013/n3804.html" target="_top">
	  N3804
	</a>
      </td><td align="left">Any library proposal</td><td align="left">Y</td><td align="left">Library Fundamentals TS</td></tr><tr bgcolor="#C8B0B0"><td align="left">
	<a class="link" href="https://www.open-std.org/JTC1/SC22/WG21/docs/papers/2014/n3866.html" target="_top">
	  N3866
	</a>
      </td><td align="left">Invocation type traits, but dropping function_call_operator.</td><td align="left">N</td><td align="left">Library Fundamentals TS</td></tr><tr><td align="left">
	<a class="link" href="" target="_top">
	  N3905
	</a>
      </td><td align="left">Faster string searching (Boyer-Moore et al.)</td><td align="left">Y</td><td align="left">Library Fundamentals TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3915.pdf" target="_top">
	  N3915
	</a>
      </td><td align="left">apply() call a function with arguments from a tuple</td><td align="left">Y</td><td align="left">Library Fundamentals TS</td></tr><tr bgcolor="#B0B0B0"><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3916.pdf" target="_top">
	  N3916
	</a>
      </td><td align="left">Polymorphic memory resources</td><td align="left">Partial (missing pool resource and buffer resource classes)</td><td align="left">Library Fundamentals TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3920.html" target="_top">
	  N3920
	</a>
      </td><td align="left">Extending shared_ptr to support arrays</td><td align="left">Y</td><td align="left">Library Fundamentals TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3921.html" target="_top">
	  N3921
	</a>
      </td><td align="left"><code class="code">string_view</code>: a non-owning reference to a string</td><td align="left">Y</td><td align="left">Library Fundamentals TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3925.pdf" target="_top">
	  N3925
	</a>
      </td><td align="left">A sample proposal</td><td align="left">Y</td><td align="left">Library Fundamentals TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3932.htm" target="_top">
	  N3932
	</a>
      </td><td align="left">Variable Templates For Type Traits</td><td align="left">Y</td><td align="left">Library Fundamentals TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4100.pdf" target="_top">
	  N4100
	</a>
      </td><td align="left">File System</td><td align="left">Y</td><td align="left">
	Link with
	<a class="link" href="using_dynamic_or_shared.html#manual.intro.using.linkage.experimental" title="Experimental Library Extensions">
	<code class="option">-lstdc++fs</code></a>
      </td></tr></tbody></table></div></div><br class="table-break" /><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="iso.2014.specific"></a>Implementation Specific Behavior</h4></div></div></div><div class="section"><div class="titlepage"><div><div><h5 class="title"><a id="iso.2014.filesystemts"></a>Filesystem TS</h5></div></div></div><p>
      <span class="emphasis"><em>2.1 POSIX conformance [fs.conform.9945]</em></span>
      The behavior of the filesystem library implementation will depend on
      the target operating system. Some features will not be supported
      on some targets. Symbolic links and file permissions
      are not supported on Windows.
    </p><p>
      <span class="emphasis"><em>15.30 Rename [fs.op.rename]</em></span>
      On Windows, <code class="code">experimental::filesystem::rename</code>
      is implemented by calling <code class="code">MoveFileExW</code> and so
      does not meet the requirements of POSIX <code class="code">rename</code>
      when one or both of the paths resolves to an existing directory.
      Specifically, it is possible to rename a directory so it replaces
      a non-directory (POSIX requires an error in that case),
      and it is not possible to rename a directory to replace another
      directory (POSIX requires that to work if the directory being
      replaced is empty).
    </p></div></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="status.iso.2017"></a>C++ 2017</h3></div></div></div><p>
In this implementation the <code class="literal">-std=gnu++17</code> or
<code class="literal">-std=c++17</code> flag must be used to enable language
and library
features. See <a class="link" href="using.html#manual.intro.using.flags" title="Command Options">dialect</a>
options. The pre-defined symbol
<code class="constant">__cplusplus</code> is used to check for the
presence of the required flag.
GCC 9.1 was the first release with non-experimental C++17 support,
so the API and ABI of features added in C++17 is only stable
since that release.
</p><p>
This section describes the C++17 and library TS support in mainline GCC,
not in any particular release.
</p><p>
The following table lists new library features that are included in
the C++17 standard. The "Proposal" column provides a link to the
ISO C++ committee proposal that describes the feature, while the "Status"
column indicates the first version of GCC that contains an implementation of
this feature (if it has been implemented).
The "SD-6 Feature Test" column shows the corresponding macro or header from
<a class="link" href="https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations" target="_top">SD-6:
Feature-testing recommendations for C++</a>.
</p><div class="table"><a id="table.cxx17_features"></a><p class="title"><strong>Table 1.5. C++ 2017 Library Features</strong></p><div class="table-contents"><table class="table" summary="C++ 2017 Library Features" border="1"><colgroup><col align="left" class="c1" /><col align="left" class="c2" /><col align="left" class="c3" /><col align="left" class="c4" /></colgroup><thead><tr><th align="left">Library Feature</th><th align="left">Proposal</th><th align="left">Status</th><th align="left">SD-6 Feature Test</th></tr></thead><tbody><tr><td align="left">
	<code class="code">constexpr std::hardware_{constructive,destructive}_interference_size</code>
      </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0154r1.html" target="_top">
	P0154R1
	</a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_hardware_interference_size &gt;= 201603</code> </td></tr><tr><td align="left"> Core Issue 1776: Replacement of class objects containing reference members</td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0137r1.html" target="_top">
	P0137R1
	</a>
      </td><td align="center"> 7.1 </td><td align="left"> <code class="code">__cpp_lib_launder &gt;= 201606</code> </td></tr><tr><td align="left">Wording for <code class="code">std::uncaught_exceptions</code></td><td align="left">
	<a class="link" href="https://www.open-std.org/JTC1/sc22/WG21/docs/papers/2014/n4259.pdf" target="_top">
	  N4259
	</a>
      </td><td align="center">6.1</td><td align="left"><code class="code">__cpp_lib_uncaught_exceptions &gt;= 201411</code></td></tr><tr><td align="left"> C++17 should refer to C11 instead of C99 </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0063r3.html" target="_top">
	P0063R3
	</a>
      </td><td align="center"> 9.1 </td><td align="left"> </td></tr><tr><td align="left"> Variant: a type-safe union for C++17 </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0088r3.html" target="_top">
	P0088R3
	</a>
      </td><td align="center"> 7.1 </td><td align="left"> <code class="code">__has_include(&lt;variant&gt;)</code>,
              <code class="code">__cpp_lib_variant &gt;= 201603</code>
              (since 7.3, see Note 1)
      </td></tr><tr><td align="left"> Library Fundamentals V1 TS Components: <code class="code">optional</code> </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html" target="_top">
	P0220R1
	</a>
      </td><td align="center"> 7.1 </td><td align="left"> <code class="code">__has_include(&lt;optional&gt;)</code>,
              <code class="code">__cpp_lib_optional &gt;= 201603</code>
              (since 7.3, see Note 1)
      </td></tr><tr><td align="left"> Library Fundamentals V1 TS Components: <code class="code">any</code> </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html" target="_top">
	P0220R1
	</a>
      </td><td align="center"> 7.1 </td><td align="left"> <code class="code">__has_include(&lt;any&gt;)</code>,
              <code class="code">__cpp_lib_any &gt;= 201603</code>
              (since 7.3, see Note 1)
      </td></tr><tr><td align="left"> Library Fundamentals V1 TS Components: <code class="code">string_view</code> </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html" target="_top">
	P0220R1
	</a>
      </td><td align="center"> 7.1 </td><td align="left"> <code class="code">__has_include(&lt;string_view&gt;)</code>,
              <code class="code">__cpp_lib_string_view &gt;= 201603</code>
              (since 7.3, see Note 1)
      </td></tr><tr><td align="left"> Library Fundamentals V1 TS Components: <code class="code">memory_resource</code> </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html" target="_top">
	P0220R1
	</a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__has_include(&lt;memory_resource&gt;)</code>,
              <code class="code">__cpp_lib_memory_resource &gt;= 201603</code>
      </td></tr><tr><td align="left"> Library Fundamentals V1 TS Components: <code class="code">apply</code> </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html" target="_top">
	P0220R1
	</a>
      </td><td align="center"> 7.1 </td><td align="left"> <code class="code">__cpp_lib_apply &gt;= 201603</code> </td></tr><tr><td align="left"> Library Fundamentals V1 TS Components: <code class="code">shared_ptr&lt;T[]&gt;</code> </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html" target="_top">
	P0220R1
	</a>
      </td><td align="center"> 7.1 </td><td align="left"> <code class="code">__cpp_lib_shared_ptr_arrays &gt;= 201603</code> </td></tr><tr><td align="left"> Library Fundamentals V1 TS Components: Searchers </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html" target="_top">
	P0220R1
	</a>
      </td><td align="center"> 7.1 </td><td align="left"> <code class="code">__cpp_lib_boyer_moore_searcher &gt;= 201603</code> </td></tr><tr><td align="left"> Library Fundamentals V1 TS Components: Sampling </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html" target="_top">
	P0220R1
	</a>
      </td><td align="center"> 7.1 </td><td align="left"> <code class="code">__cpp_lib_sample &gt;= 201603</code> </td></tr><tr><td align="left"> Constant View: A proposal for a <code class="code">std::as_const</code> helper function template	</td><td align="left">
	<a class="link" href="" target="_top">
	P0007R1
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_as_const &gt;= 201510 </code></td></tr><tr><td align="left"> Improving pair and tuple </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4387" target="_top">
	N4387
	</a>
      </td><td align="center"> 6.1 </td><td align="left"> N/A </td></tr><tr><td align="left"> <code class="code">make_from_tuple</code>: apply for construction </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0209r2.pdf" target="_top">
	P0209R2
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_make_from_tuple &gt;= 201606 </code></td></tr><tr bgcolor="#C8B0B0"><td align="left">
        Removing <code class="code">auto_ptr</code>, <code class="code">random_shuffle()</code>,
        And Old <code class="code">&lt;functional&gt;</code> Stuff
      </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4190.htm" target="_top">
	  N4190
	</a>
      </td><td align="center">No (kept for backwards compatibility)</td><td align="left"> </td></tr><tr><td align="left"> Deprecating Vestigial Library Parts in C++17 </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0174r2.html" target="_top">
	P0174R2
	</a>
      </td><td align="center"> 12.1 </td><td align="left"> </td></tr><tr><td align="left"> Making <code class="code">std::owner_less</code> more flexible </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0074r0.html" target="_top">
	P0074R0
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_transparent_operators &gt;= 201510 </code></td></tr><tr><td align="left"> <code class="code">std::addressof</code> should be constexpr </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0304r0.html#2296" target="_top">
	LWG2296
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_addressof_constexpr &gt;= 201603 </code></td></tr><tr><td align="left"> Safe conversions in <code class="code">unique_ptr&lt;T[]&gt;</code> </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4089.pdf" target="_top">
	N4089
	</a>
      </td><td align="center"> 6 </td><td align="left"> </td></tr><tr><td align="left"> LWG 2228: Missing SFINAE rule in unique_ptr templated assignment </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4366.html" target="_top">
	  N4366
	</a>
      </td><td align="center"> 6 </td><td align="left"> </td></tr><tr><td align="left"> Re-enabling <code class="code">shared_from_this</code></td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0033r1.html" target="_top">
	P0033R1
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code">__cpp_lib_enable_shared_from_this &gt;= 201603</code></td></tr><tr><td align="left"> A proposal to add <code class="code">invoke</code> function template </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4169.html" target="_top">
	N4169
	</a>
      </td><td align="center"> 6.1 </td><td align="left"><code class="code"> __cpp_lib_invoke &gt;= 201411 </code></td></tr><tr><td align="left">TriviallyCopyable <code class="code">reference_wrapper</code> </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4277.html" target="_top">
	  N4277
	</a>
      </td><td align="center"> 5.1 </td><td align="left"> </td></tr><tr><td align="left"> Adopt <code class="code">not_fn</code> from Library Fundamentals 2 for C++17 </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0005r4.html" target="_top">
	P0005R4
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code">__cpp_lib_not_fn &gt;= 201603</code></td></tr><tr><td align="left"> Fixes for <code class="code">not_fn</code> </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0358r1.html" target="_top">
	P0358R1
	</a>
      </td><td align="center"> 7.1 </td><td align="left"> </td></tr><tr><td align="left"> Fixing a design mistake in the searchers interface in Library Fundamentals </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0253r1.pdf" target="_top">
	P0253R1
	</a>
      </td><td align="center"> 7.1 </td><td align="left"> </td></tr><tr><td align="left"> Extending memory management tools </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0040r3.html" target="_top">
	P0040R3
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code">__cpp_lib_raw_memory_algorithms &gt;= 201606L</code></td></tr><tr><td align="left"> <code class="code">shared_ptr::weak_type</code></td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0163r0.html" target="_top">
	P0163R0
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_shared_ptr_weak_type &gt;= 201606</code></td></tr><tr><td align="left">Transformation Trait Alias <code class="code">void_t</code></td><td align="left">
	<a class="link" href="https://www.open-std.org/JTC1/sc22/WG21/docs/papers/2014/n3911.pdf" target="_top">
	  N3911
	</a>
      </td><td align="center">6.1</td><td align="left"><code class="code"> __cpp_lib_void_t &gt;= 201411</code></td></tr><tr><td align="left"> Wording for <code class="code">bool_constant</code>, revision 1 </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4389.html" target="_top">
	  N4389
	</a>
      </td><td align="center">6.1</td><td align="left"><code class="code"> __cpp_lib_bool_constant &gt;= 201505</code></td></tr><tr><td align="left"> Adopt Type Traits Variable Templates from Library Fundamentals TS for C++17</td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0006r0.html" target="_top">
	P0006R0
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_type_trait_variable_templates &gt;= 201510 </code></td></tr><tr><td align="left"> Logical Operator Type Traits</td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0013r1.html" target="_top">
	P0013R1
	</a>
      </td><td align="center"> 6.1 </td><td align="left"><code class="code"> __cpp_lib_logical_traits &gt;= 201510 </code></td></tr><tr><td align="left"> Adding [nothrow-]swappable traits </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0185r1.html" target="_top">
	P0185R1
	</a>
      </td><td align="center"> 7.1 (<code class="code">__is_swappable</code> available since 6.1)</td><td align="left"><code class="code"> __cpp_lib_is_swappable &gt;= 201603 </code></td></tr><tr><td align="left"> <code class="code">is_callable</code>, the missing INVOKE related trait</td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0077r2.html" target="_top">
	P0077R2
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_is_invocable &gt;= 201703 </code></td></tr><tr><td align="left"> has_unique_object_representations </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0258r2.html" target="_top">
	P0258R2
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_has_unique_object_representations &gt;= 201606 </code></td></tr><tr><td align="left"> Polishing <code class="code">&lt;chrono&gt;</code> </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0092r1.html" target="_top">
	P0092R1
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_chrono &gt;= 201510 </code></td></tr><tr><td align="left"> Adding more constexpr to <code class="code">&lt;chrono&gt;</code> </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0505r0.html" target="_top">
	P0505R0
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_chrono &gt;= 201611 </code>
             (since 7.3, see Note 2)
      </td></tr><tr><td align="left"> Constexpr for <code class="code">std::char_traits</code> </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0426r1.html" target="_top">
	P0426R1
	</a>
      </td><td align="center"> 8.1 </td><td align="left"><code class="code"> __cpp_lib_constexpr_string &gt;= 201611 </code></td></tr><tr><td align="left"> Integrating <code class="code">std::string_view</code> and <code class="code">std::string</code> </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0254r2.pdf" target="_top">
	P0254R2
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> </code></td></tr><tr><td align="left"> Give 'std::string' a non-const '.data()' member function </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0272r1.html" target="_top">
	P0272R1
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> </code></td></tr><tr><td align="left">Cleaning-up noexcept in the Library</td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4258.pdf" target="_top">
	  N4258
	</a>
      </td><td align="center">6.1</td><td align="left"><code class="code"> __cpp_lib_allocator_traits_is_always_equal &gt;= 201411 </code></td></tr><tr><td align="left">Contiguous Iterators </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4284.html" target="_top">
	  N4284
	</a>
      </td><td align="center">N/A</td><td align="left"> </td></tr><tr><td align="left"> Minimal incomplete type support for standard containers </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4510.html" target="_top">
	N4510
	</a>
      </td><td align="center"> 3.0 </td><td align="left"><code class="code"> __cpp_lib_incomplete_container_elements &gt;= 201505 </code>
	     (since 6.2, see Note 2)
      </td></tr><tr><td align="left"> Emplace return type </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0084r2.pdf" target="_top">
	P0084R2
	</a>
      </td><td align="center"> 7.1 </td><td align="left"> </td></tr><tr><td align="left">Improved insertion interface for unique-key maps</td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4279.html" target="_top">
	  N4279
	</a>
      </td><td align="center"> 6.1 </td><td align="left"><code class="code"> __cpp_lib_map_try_emplace &gt;= 201411</code>,
	     <code class="code"> __cpp_lib_unordered_map_try_emplace &gt;= 201411</code>
      </td></tr><tr><td align="left"> Splicing Maps and Sets </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0083r3.pdf" target="_top">
	P0083R3
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_node_extract &gt;= 201606 </code></td></tr><tr><td align="left">Non-member <code class="code">size()</code> and more</td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4280.pdf" target="_top">
	  N4280
	</a>
      </td><td align="center"> 6.1 </td><td align="left"><code class="code"> __cpp_lib_nonmember_container_access &gt;= 201411 </code></td></tr><tr><td align="left"> A Proposal to Add Constexpr Modifiers to <code class="code">reverse_iterator</code>, <code class="code">move_iterator</code>, <code class="code">array</code> and Range Access </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0031r0.html" target="_top">
	P0031R0
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_array_constexpr &gt;= 201603 </code></td></tr><tr bgcolor="#B0B0B0"><td align="left"> The Parallelism TS Should be Standardized	 </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0024r2.html" target="_top">
	P0024R2
	</a>
      </td><td align="center"> 9.1 </td><td align="left"><code class="code"> __has_include(&lt;execution&gt;)</code>,
	     <code class="code"> __cpp_lib_execution &gt;= 201603 </code>,
	     <code class="code"> __cpp_lib_parallel_algorithm &gt;= 201603 </code>
             (requires linking with <code class="code">-ltbb</code>, see Note 3)
      </td></tr><tr><td align="left"> An algorithm to "clamp" a value between a pair of boundary values </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0025r0.html" target="_top">
	P0025R0
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_clamp &gt;= 201603 </code></td></tr><tr><td align="left"> Adopt Selected Library Fundamentals V2 Components for C++17 </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0295r0.pdf" target="_top">
	P0295R0
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_gcd_lcm &gt;= 201606 </code></td></tr><tr><td align="left"> Proposal to Introduce a 3-Argument Overload to <code class="code">std::hypot</code> </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/p0030r1.pdf" target="_top">
	P0030R1
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_hypot &gt;= 201603 </code></td></tr><tr><td align="left"> Mathematical Special Functions for C++17 </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0226r1.pdf" target="_top">
	P0226R1
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_math_special_functions &gt;= 201603 </code>
	     (see Note 4)
      </td></tr><tr><td align="left">Adopt the File System TS for C++17	 </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0218r1.html" target="_top">
	P0218R1
	</a>
      </td><td align="center"> 8.1 </td><td align="left"><code class="code"> __has_include(&lt;filesystem&gt;)</code>,
	     <code class="code"> __cpp_lib_filesystem &gt;= 201603 </code>
	     (GCC 8.x requires linking with <code class="code">-lstdc++fs</code>)
      </td></tr><tr><td align="left"> Relative Paths for Filesystem</td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0219r1.html" target="_top">
	P0219R1
	</a>
      </td><td align="center"> 8.1 </td><td align="left"><code class="code"> __cpp_lib_filesystem &gt;= 201606 </code></td></tr><tr><td align="left"> Adapting string_view by filesystem paths </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0392r0.pdf" target="_top">
	P0392R0
	</a>
      </td><td align="center"> 8.1 </td><td align="left"><code class="code"> __cpp_lib_filesystem &gt;= 201606 </code></td></tr><tr><td align="left"> Directory Entry Caching for Filesystem </td><td align="left">
       <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0317r1.html" target="_top">
       P0317R1
       </a>
      </td><td align="center"> 8.1 </td><td align="left"><code class="code"> __cpp_lib_filesystem &gt;= 201703 </code></td></tr><tr><td align="left"> constexpr <code class="code">atomic&lt;T&gt;::is_always_lock_free</code>	 </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0152r1.html" target="_top">
	P0152R1
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_atomic_is_always_lock_free &gt;= 201603 </code></td></tr><tr><td align="left">A proposal to add <code class="code">shared_mutex</code> (untimed) (Revision 4)</td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4508.html" target="_top">
	  N4508
	</a>
      </td><td align="center"> 6.1 </td><td align="left"><code class="code"> __cpp_lib_shared_mutex &gt;= 201505 </code></td></tr><tr><td align="left"> Variadic <code class="code">lock_guard</code> (Rev. 5) </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0156r2.html" target="_top">
	P0156R2
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_scoped_lock &gt;= 201703 </code></td></tr><tr><td align="left"> A byte type definition </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0298r3.pdf" target="_top">
	P0298R3
	</a>
      </td><td align="center"> 7.1 </td><td align="left"><code class="code"> __cpp_lib_byte &gt;= 201603 </code> (since 7.3, see Note 2)
      </td></tr><tr><td align="left"> Elementary string conversions </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0067r5.html" target="_top">
	P0067R5
	</a>
      </td><td align="center"> 11.1 (integral types supported since 8.1) </td><td align="left"><code class="code"> __has_include(&lt;charconv&gt;)</code>,
             <code class="code"> __cpp_lib_to_chars &gt;= 201611 </code></td></tr><tr><td align="left"> Homogeneous interface for variant, any and optional </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0032r3.pdf" target="_top">
	P0032R3
	</a>
      </td><td align="center"> 7.1  </td><td align="left">
             <code class="code"> __cpp_lib_any &gt;= 201606 </code>,
             <code class="code"> __cpp_lib_optional &gt;= 201606 </code>,
             <code class="code"> __cpp_lib_variant &gt;= 201606 </code>
      </td></tr><tr><td align="left"> Making Optional Greater Equal Again </td><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0307r2.pdf" target="_top">
	P0307R2
	</a>
      </td><td align="center"> 7.1  </td><td align="left"> <code class="code"> __cpp_lib_optional &gt;= 201606 </code> </td></tr></tbody></table></div></div><br class="table-break" /><p>
Note 1: This feature is supported in GCC 7.1 and 7.2 but before GCC 7.3 the
<code class="code">__cpp_lib</code> macro is not defined, and compilation will fail if the
header is included without using <code class="option">-std</code> to enable C++17 support.
</p><p>
Note 2: This feature is supported in older releases but the
<code class="code">__cpp_lib</code> macro is not defined to the right value
(or not defined at all) until the version shown in parentheses.
</p><p>
Note 3: The Parallel Algorithms have an external dependency on Intel TBB 2018
or later. If the <code class="filename">&lt;execution&gt;</code>
header is included then <code class="code">-ltbb</code> must be used to link to TBB.
</p><p>
Note 4: The mathematical special functions are enabled in C++17 mode from
GCC 7.1 onwards. For GCC 6.x or for C++11/C++14 define
<code class="code">__STDCPP_WANT_MATH_SPEC_FUNCS__</code> to a non-zero value
and test for <code class="code">__STDCPP_MATH_SPEC_FUNCS__ &gt;= 201003L</code>.
</p><p>
The following status table is based on the table of contents of
ISO/IEC 14882:2017.
Some subclauses are not shown in the table where the content is unchanged
since C++14 and the implementation is complete.
</p><div class="table"><a id="table.cxx17_status"></a><p class="title"><strong>Table 1.6. C++ 2017 Implementation Status</strong></p><div class="table-contents"><table class="table" summary="C++ 2017 Implementation Status" border="1"><colgroup><col align="left" class="c1" /><col align="left" class="c2" /><col align="left" class="c3" /><col align="left" class="c4" /></colgroup><thead><tr><th align="left">Section</th><th align="left">Description</th><th align="left">Status</th><th align="left">Comments</th></tr></thead><tbody><tr><td align="left">
	<span class="emphasis"><em>21</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Language support</em></span>
      </td></tr><tr><td align="left">21.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">21.2</td><td align="left">Common definitions</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">21.3</td><td align="left">Implementation properties</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">21.3.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">21.3.2</td><td align="left">Header <code class="code">&lt;limits&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">21.3.3</td><td align="left">Floating-point type properties</td><td align="left"> </td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">21.3.3.1</td><td align="left"><code class="code">float_round_style</code></td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">21.3.3.2</td><td align="left"><code class="code">float_denorm_style</code></td><td align="left">N</td><td align="left"> </td></tr><tr><td align="left">21.3.4</td><td align="left">Class template <code class="code">numeric_limits</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.3.5</td><td align="left">Header <code class="code">&lt;climits&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.3.6</td><td align="left">Header <code class="code">&lt;cfloat&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.4</td><td align="left">Integer types</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">21.4.1</td><td align="left">Header <code class="code">&lt;cstdint&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">21.5</td><td align="left">Start and termination</td><td align="left">Partial</td><td align="left">C library dependency for quick_exit, at_quick_exit</td></tr><tr><td align="left">21.6</td><td align="left">Dynamic memory management</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">21.6.1</td><td align="left">Header <code class="code">&lt;new&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">21.6.2</td><td align="left">Storage allocation and deallocation</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.6.3</td><td align="left">Storage allocation errors</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.6.4</td><td align="left">Pointer optimization barrier</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.6.5</td><td align="left">Hardware interference size</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.7</td><td align="left">Type identification</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.8</td><td align="left">Exception handling</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">21.8.1</td><td align="left">Header <code class="code">&lt;exception&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">21.8.2</td><td align="left">Class exception</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.8.3</td><td align="left">Class bad_exception</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.8.4</td><td align="left">Abnormal termination</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.8.5</td><td align="left"><code class="code">uncaught_exceptions</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.8.6</td><td align="left">Exception Propagation</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.8.7</td><td align="left"><code class="code">nested_exception</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.9</td><td align="left">Initializer lists</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">21.10</td><td align="left">Other runtime support</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>22</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Diagnostics</em></span>
      </td></tr><tr><td align="left">22.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">22.2</td><td align="left">Exception classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.3</td><td align="left">Assertions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.4</td><td align="left">Error numbers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">22.5</td><td align="left">System error support</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>23</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>General utilities</em></span>
      </td></tr><tr><td align="left">23.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.2</td><td align="left">Utility components</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.2.1</td><td align="left">Header <code class="code">&lt;utility&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.2.2</td><td align="left">Operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.2.3</td><td align="left"><code class="code">swap</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.2.4</td><td align="left"><code class="code">exchange</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.2.5</td><td align="left">Forward/move helpers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.2.6</td><td align="left">Function template <code class="code">as_const</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.2.7</td><td align="left">Function template <code class="code">declval</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.2.8</td><td align="left">Primitive numeric output conversion</td><td align="left">Partial</td><td align="left"> </td></tr><tr><td align="left">23.2.9</td><td align="left">Primitive numeric input conversion</td><td align="left">Partial</td><td align="left"> </td></tr><tr><td align="left">23.3</td><td align="left">Compile-time integer sequences</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.4</td><td align="left">Pairs</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.5</td><td align="left">Tuples</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.6</td><td align="left">Optional objects</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.7</td><td align="left">Variants</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.8</td><td align="left">Storage for any type</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.9</td><td align="left">Bitsets</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.10</td><td align="left">Memory</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.10.1</td><td align="left">In general</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.10.2</td><td align="left">Header <code class="code">&lt;memory&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.10.3</td><td align="left">Pointer traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.10.4</td><td align="left">Pointer safety</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.10.5</td><td align="left">Align</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.10.6</td><td align="left">Allocator argument tag</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.10.7</td><td align="left"><code class="code">uses_allocator</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.10.8</td><td align="left">Allocator traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.10.9</td><td align="left">The default allocator</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.10.10</td><td align="left">Specialized algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.10.11</td><td align="left">C library memory allocation</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.11</td><td align="left">Smart pointers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.11.1</td><td align="left">Class template <code class="code">unique_ptr</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.11.2</td><td align="left">Shared-ownership pointers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.12</td><td align="left">Memory resources</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.12.1</td><td align="left">Header <code class="code">&lt;memory_resource&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.12.2</td><td align="left">Class <code class="code">memory_resource</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.12.3</td><td align="left">Class template <code class="code">polymorphic_allocator</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.12.4</td><td align="left">Access to program-wide <code class="code">memory_resource</code> objects</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.12.5</td><td align="left">Pool resource classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.12.6</td><td align="left">Class <code class="code">monotonic_buffer_resource</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.13</td><td align="left">Class template <code class="code">scoped_allocator_adaptor</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.14</td><td align="left">Function objects</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.14.1</td><td align="left">Header <code class="code">&lt;functional&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.14.2</td><td align="left">Definitions</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.14.3</td><td align="left">Requirements</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.14.4</td><td align="left">Function template <code class="code">invoke</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.14.5</td><td align="left">Class template <code class="code">reference_wrapper</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.14.6</td><td align="left">Arithmetic operation</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.14.7</td><td align="left">Comparisons</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.14.8</td><td align="left">Logical operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.14.9</td><td align="left">Bitwise operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.14.10</td><td align="left">Function template <code class="code">not_fn</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.14.11</td><td align="left">Function object binders</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.14.12</td><td align="left">Function template <code class="code">mem_fn</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.14.13</td><td align="left">Polymorphic function wrappers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.14.14</td><td align="left">Searchers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.14.15</td><td align="left">Class template <code class="code">hash</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.15</td><td align="left">Metaprogramming and type traits</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.15.1</td><td align="left">Requirements</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.15.2</td><td align="left">Header <code class="code">&lt;type_traits&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.15.3</td><td align="left">Helper classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.15.4</td><td align="left">Unary Type Traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.15.5</td><td align="left">Type property queries</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.15.6</td><td align="left">Relationships between types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.15.7</td><td align="left">Transformations between types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.15.8</td><td align="left">Logical operator traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.16</td><td align="left">Compile-time rational arithmetic</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.17.1</td><td align="left">In general</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.17.2</td><td align="left">Header <code class="code">&lt;chrono&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.17</td><td align="left">Time utilities</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.17.3</td><td align="left">Clock requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.17.4</td><td align="left">Time-related traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.17.5</td><td align="left">Class template <code class="code">duration</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.17.6</td><td align="left">Class template <code class="code">time_point</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.17.7</td><td align="left">Clocks</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.17.8</td><td align="left">Header <code class="code">&lt;ctime&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.18</td><td align="left">Class <code class="code">type_index</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.19</td><td align="left">Execution policies</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.19.1</td><td align="left">In general</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.19.2</td><td align="left">Header <code class="code">&lt;execution&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">23.19.3</td><td align="left">Execution policy type trait</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.19.4</td><td align="left">Sequenced execution policy</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.19.5</td><td align="left">Parallel execution policy</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.19.6</td><td align="left">Parallel and unsequenced execution policy</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">23.19.7</td><td align="left">Execution policy objects</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>24</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Strings</em></span>
      </td></tr><tr><td align="left">24.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">24.2</td><td align="left">Character traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.3</td><td align="left">String classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.4</td><td align="left">String view classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.4.1</td><td align="left">Header <code class="code">&lt;string_view&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.4.2</td><td align="left">Class template <code class="code">basic_string_view</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.4.3</td><td align="left">Non-member comparison functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.4.4</td><td align="left">Inserters and extractors</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.4.5</td><td align="left">Hash support</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">24.4.6</td><td align="left">Suffix for <code class="code">basic_string_view</code> literals</td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">24.5</td><td align="left">Null-terminated sequence utilities</td><td align="left">Partial</td><td align="left">C library dependency. </td></tr><tr><td align="left">
	<span class="emphasis"><em>25</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Localization</em></span>
      </td></tr><tr><td align="left">25.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">25.2</td><td align="left">Header <code class="code">&lt;locale&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">25.3</td><td align="left">Locales</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">25.4</td><td align="left">Standard <code class="code">locale</code> categories</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">25.5</td><td align="left">C Library Locales</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>26</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Containers</em></span>
      </td></tr><tr><td align="left">26.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">26.2</td><td align="left">Container requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.3</td><td align="left">Sequence containers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.4</td><td align="left">Associative containers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.5</td><td align="left">Unordered associative containers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">26.6</td><td align="left">Container adaptors</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>27</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Iterators</em></span>
      </td></tr><tr><td align="left">27.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.2</td><td align="left">Iterator requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.3</td><td align="left">Header <code class="code">&lt;iterator&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.4</td><td align="left">Iterator primitives</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.5</td><td align="left">Iterator adaptors</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.6</td><td align="left">Stream iterators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.7</td><td align="left">Range access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">27.8</td><td align="left">Container access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>28</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Algorithms</em></span>
      </td></tr><tr><td align="left">28.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">28.2</td><td align="left">Header <code class="code">&lt;algorithm&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">28.3</td><td align="left">Algorithms requirements</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">28.4</td><td align="left">Parallel algorithms</td><td align="left"> </td><td align="left">Using <a class="link" href="https://github.com/llvm/llvm-project/tree/main/pstl" target="_top">PSTL</a></td></tr><tr><td align="left">28.5</td><td align="left">Non-modifying sequence operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.6</td><td align="left">Mutating sequence operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.7</td><td align="left">Sorting and related operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">28.8</td><td align="left">C library algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
      <span class="emphasis"><em>29</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Numerics</em></span>
      </td></tr><tr><td align="left">29.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">29.2</td><td align="left">Definitions</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">29.3</td><td align="left">Numeric type requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.4</td><td align="left">The floating-point environment</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.5</td><td align="left">Complex numbers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.6</td><td align="left">Random number generation</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.7</td><td align="left">Numeric arrays</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.8</td><td align="left">Generalized numeric operations</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">29.8.1</td><td align="left">Header <code class="code">&lt;numeric&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">29.8.2</td><td align="left">Accumulate</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.8.3</td><td align="left">Reduce</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.8.4</td><td align="left">Inner product</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.8.5</td><td align="left">Transform reduce</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.8.6</td><td align="left">Partial sum</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.8.7</td><td align="left">Exclusive scan</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.8.8</td><td align="left">Inclusive scan</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.8.9</td><td align="left">Transform exclusive scan</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.8.10</td><td align="left">Transform inclusive scan</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.8.11</td><td align="left">Adjacent difference</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.8.12</td><td align="left">Iota</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.8.13</td><td align="left">Greatest common divisor</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.8.14</td><td align="left">Least common multiple</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.9</td><td align="left">Mathematical functions for floating-point types</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">29.9.1</td><td align="left">Header <code class="code">&lt;cmath&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">29.9.2</td><td align="left">Absolute values</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.9.3</td><td align="left">Three-dimensional hypotenuse</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.9.4</td><td align="left">Classification / comparison functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">29.9.5</td><td align="left">Mathematical special functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>30</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Input/output library</em></span>
      </td></tr><tr><td align="left">30.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.2</td><td align="left">Iostreams requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.2.1</td><td align="left">Imbue Limitations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.2.2</td><td align="left">Positioning Type Limitations</td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">30.2.3</td><td align="left">Thread safety</td><td align="left">Partial</td><td align="left"> </td></tr><tr><td align="left">30.3</td><td align="left">Forward declarations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.4</td><td align="left">Standard iostream objects</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.5</td><td align="left">Iostreams base classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.6</td><td align="left">Stream buffers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.7</td><td align="left">Formatting and manipulators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.8</td><td align="left">String-based streams</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.9</td><td align="left">File-based streams</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.10</td><td align="left">File systemss</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">30.11</td><td align="left">C library files</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>31</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Regular expressions</em></span>
      </td></tr><tr><td align="left">31.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">31.2</td><td align="left">Definitions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">31.3</td><td align="left">Requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">31.4</td><td align="left">Header <code class="code">&lt;regex&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">31.5</td><td align="left">Namespace <code class="code">std::regex_constants</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">31.6</td><td align="left">Class <code class="code">regex_error</code></td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">31.7</td><td align="left">Class template <code class="code">regex_traits</code></td><td align="left">Partial</td><td align="left"><code class="code">transform_primary</code> is not correctly implemented</td></tr><tr><td align="left">31.8</td><td align="left">Class template <code class="code">basic_regex</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">31.9</td><td align="left">Class template <code class="code">sub_match</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">31.10</td><td align="left">Class template <code class="code">match_results</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">31.11</td><td align="left">Regular expression algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">31.12</td><td align="left">Regular expression Iterators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">31.13</td><td align="left">Modified ECMAScript regular expression grammar</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>32</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Atomic operations</em></span>
      </td></tr><tr><td align="left">32.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">32.2</td><td align="left">Header <code class="code">&lt;atomic&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">32.3</td><td align="left">Type aliases</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">32.4</td><td align="left">Order and consistency</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">32.5</td><td align="left">Lock-free property</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">32.6</td><td align="left">Class template <code class="code">&lt;atomic&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">32.7</td><td align="left">Non-member functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">32.8</td><td align="left">Flag Type and operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">32.9</td><td align="left">Fences</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>33</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Thread support</em></span>
      </td></tr><tr><td align="left">33.1</td><td align="left">General</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.2</td><td align="left">Requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.3</td><td align="left">Threads</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">33.3.1</td><td align="left">Header <code class="code">thread</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">33.3.2</td><td align="left">Class <code class="code">thread</code></td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">33.3.2.1</td><td align="left">Class <code class="code">thread</code></td><td align="left">Partial</td><td align="left"><code class="code">thread::id</code> comparisons not well-defined</td></tr><tr><td align="left">33.3.3</td><td align="left">Namespace <code class="code">this_thread</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.4</td><td align="left">Mutual exclusion</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">33.4.3</td><td align="left">Mutex requirements</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">33.4.3.1</td><td align="left">In general</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">33.4.3.2</td><td align="left">Mutex types</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">33.4.3.2.1</td><td align="left">Class <code class="code">mutex</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.4.3.2.2</td><td align="left">Class <code class="code">recursive_mutex</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.4.3.3</td><td align="left">Timed mutex types</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">33.4.3.3.1</td><td align="left">Class <code class="code">timed_mutex</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.4.3.3.2</td><td align="left">Class <code class="code">recursive_timed_mutex</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.4.3.4</td><td align="left">Shared mutex types</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">33.4.3.4.1</td><td align="left">Class <code class="code">shared_mutex</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.4.3.5</td><td align="left">Shared timed mutex types</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">33.4.3.5.1</td><td align="left">Class <code class="code">shared_timed_mutex</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.4.4</td><td align="left">Locks</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">33.4.4.1</td><td align="left">Class template <code class="code">lock_guard</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.4.4.2</td><td align="left">Class template <code class="code">scoped_guard</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.4.4.3</td><td align="left">Class template <code class="code">unique_lock</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.4.4.4</td><td align="left">Class template <code class="code">shared_lock</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.4.5</td><td align="left">Generic locking algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.4.6</td><td align="left">Call once</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">33.4.6.1</td><td align="left">Struct <code class="code">once_flag</code></td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">33.4.6.2</td><td align="left">Function <code class="code">call_once</code></td><td align="left">Y</td><td align="left">Exception support is broken on non-Linux targets.
	See <a class="link" href="https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66146" target="_top">PR
	66146</a>.
      </td></tr><tr><td align="left">33.5</td><td align="left">Condition variables</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.5.1</td><td align="left">Class <code class="code">condition_variable</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.5.2</td><td align="left">Class <code class="code">condition_variable_any</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.6</td><td align="left">Futures</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">33.6.1</td><td align="left">Overview</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">33.6.2</td><td align="left">Header <code class="code">&lt;future&gt;</code></td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">33.6.3</td><td align="left">Error handling</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.6.4</td><td align="left">Class <code class="code">future_error</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.6.5</td><td align="left">Shared state</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.6.6</td><td align="left">Class template <code class="code">promise</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.6.7</td><td align="left">Class template <code class="code">future</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.6.8</td><td align="left">Class template <code class="code">shared_future</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.6.9</td><td align="left">Function template <code class="code">async</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">33.6.10</td><td align="left">Class template <code class="code">packaged_task</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>Appendix D</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Compatibility features</em></span>
      </td></tr><tr><td align="left">D.4</td><td align="left">C++ standard library headers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.4.1</td><td align="left">Header <code class="code">&lt;ccomplex&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.4.1</td><td align="left">Header <code class="code">&lt;cstdalign&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.4.1</td><td align="left">Header <code class="code">&lt;cstdbool&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.4.1</td><td align="left">Header <code class="code">&lt;ctgmath&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.5</td><td align="left">C standard library headers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.6</td><td align="left"><code class="code">char*</code> streams</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.7</td><td align="left"><code class="code">uncaught_exception</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.8</td><td align="left">Old adaptable function bindings</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.9</td><td align="left">The default allocator</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.10</td><td align="left">Raw storage iterator</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.11</td><td align="left">Temporary buffers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.12</td><td align="left">Deprecated type traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.13</td><td align="left">Deprecated iterator primitives</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.14</td><td align="left">Deprecated <code class="code">shared_ptr</code> observers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.15</td><td align="left">Deprecated standard code conversion facets</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">D.16</td><td align="left">Deprecated convenience conversion interfaces</td><td align="left">Y</td><td align="left"> </td></tr></tbody></table></div></div><br class="table-break" /><div class="table"><a id="table.cxx17_ts_status"></a><p class="title"><strong>Table 1.7. C++ Technical Specifications Implementation Status</strong></p><div class="table-contents"><table class="table" summary="C++ Technical Specifications Implementation Status" border="1"><colgroup><col align="left" class="c1" /><col align="left" class="c2" /><col align="left" class="c3" /><col align="left" class="c4" /></colgroup><thead><tr><th align="left">Paper</th><th align="left">Title</th><th align="left">Status</th><th align="left">Comments</th></tr></thead><tbody><tr><td align="left">
	<a class="link" href="https://www.open-std.org/JTC1/SC22/WG21/docs/papers/2014/n4076.html" target="_top">
	  N4076
	</a>
      </td><td align="left">A generalized callable negator</td><td align="left">Y</td><td align="left">Library Fundamentals 2 TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/JTC1/SC22/WG21/docs/papers/2014/n4273.htm" target="_top">
	  N4273
	</a>
      </td><td align="left">Uniform Container Erasure</td><td align="left">Y</td><td align="left">Library Fundamentals 2 TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4061.pdf" target="_top">
	  N4061
	</a>
      </td><td align="left">Greatest Common Divisor and Least Common Multiple</td><td align="left">Y</td><td align="left">Library Fundamentals 2 TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4066.htm" target="_top">
	  N4066
	</a>
      </td><td align="left">Delimited iterators</td><td align="left">Y</td><td align="left">Library Fundamentals 2 TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4282.pdf" target="_top">
	  N4282
	</a>
      </td><td align="left">The World's Dumbest Smart Pointer</td><td align="left">Y</td><td align="left">Library Fundamentals 2 TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4388.html" target="_top">
	  N4388
	</a>
      </td><td align="left">Const-Propagating Wrapper</td><td align="left">Y</td><td align="left">Library Fundamentals 2 TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4391.html" target="_top">
	  N4391
	</a>
      </td><td align="left"> <code class="code">make_array</code>, revision 4 </td><td align="left">Y</td><td align="left">Library Fundamentals 2 TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4502.pdf" target="_top">
	  N4502
	</a>
      </td><td align="left"> Support for the C++ Detection Idiom, V2 </td><td align="left">Y</td><td align="left">Library Fundamentals 2 TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4519.pdf" target="_top">
	  N4519
	</a>
      </td><td align="left"> Source-Code Information Capture </td><td align="left">Y</td><td align="left">Library Fundamentals 2 TS</td></tr><tr bgcolor="#C8B0B0"><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4521.html" target="_top">
	  N4521
	</a>
      </td><td align="left"> Merge Fundamentals V1 into V2 </td><td align="left">
        N (components from V1 are still in namespace
        <code class="code">fundamentals_v1</code>)
      </td><td align="left">Library Fundamentals 2 TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/JTC1/SC22/WG21/docs/papers/2015/p0013r1.html" target="_top">
	  P0013R1
	</a>
      </td><td align="left">Logical Operator Type Traits (revision 1)</td><td align="left">Y</td><td align="left">Library Fundamentals 2 TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4531.html" target="_top">
	  N4531
	</a>
      </td><td align="left">std::rand replacement, revision 3</td><td align="left">Y</td><td align="left">Library Fundamentals 2 TS</td></tr><tr><td align="left">
	<a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0214r9.pdf" target="_top">
	  P0214R9
	</a>
      </td><td align="left">Data-Parallel Types</td><td align="left">Y</td><td align="left">Parallelism 2 TS</td></tr></tbody></table></div></div><br class="table-break" /><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="iso.2017.specific"></a>Implementation Specific Behavior</h4></div></div></div><p>For behaviour which is also specified by previous standards,
      see <a class="link" href="status.html#iso.1998.specific" title="Implementation Specific Behavior">C++ 1998/2003 Implementation
      Specific Behavior</a> and <a class="link" href="status.html#iso.2011.specific" title="Implementation Specific Behavior">C++
      2011 Implementation Specific Behavior</a>. This section only
      documents behaviour which is new in the 2017 standard.
   </p><p>
      <span class="emphasis"><em>20.5.1.2 [headers]</em></span>
      Whether names from Annex K are declared by C++ headers depends on
      whether the underlying C library supports Annex K and declares the
      names. For the GNU C library, there is no Annex K support and so
      none of its names are declared by C++ headers.
   </p><p>
      <span class="emphasis"><em>23.6.5 [optional.bad_optional_access]</em></span>
      <code class="code">what()</code> returns <code class="literal">"bad optional access"</code>.
   </p><p>
      <span class="emphasis"><em>23.7.3 [variant.variant]</em></span>
      <code class="classname">variant</code> supports over-aligned types.
   </p><p>
      <span class="emphasis"><em>23.7.10 [variant.bad.access]</em></span>
      <code class="code">what()</code> returns one of the strings
      <code class="literal">"std::get: variant is valueless"</code>,
      <code class="literal">"std::get: wrong index for variant"</code>,
      <code class="literal">"std::visit: variant is valueless"</code>,
      or <code class="literal">"std::visit&lt;R&gt;: variant is valueless"</code>.
   </p><p>
      <span class="emphasis"><em>23.12.5.2 [memory.resource.pool.options]</em></span>
      Let S equal <code class="code">numeric_limits&lt;size_t&gt;::digits</code>.
      The limit for maximum number of blocks in a chunk is given by
      <span class="mathphrase">2<sup>N</sup>-1</span>,
      where N is <span class="mathphrase">min(19, 3 + S/2)</span>.
      The largest allocation size that will be allocated from a pool is
      <span class="mathphrase">2<sup>22</sup></span>
      when <span class="mathphrase">S &gt; 20</span>,
      otherwise 3072 when <span class="mathphrase">S &gt; 16</span>,
      otherwise 768.
   </p><p>
      <span class="emphasis"><em>23.12.6.1 [memory.resource.monotonic.buffer.ctor]</em></span>
      The default <code class="code">next_buffer_size</code> is <code class="code">128 * sizeof(void*)</code>.
      The default growth factor is <code class="code">1.5</code>.
   </p><p>
      <span class="emphasis"><em>23.15.4.3 [meta.unary.prop]</em></span>
      The predicate condition for
      <code class="code">has_unique_object_representations</code> is true for all scalar
      types except floating point types.
   </p><p>
      <span class="emphasis"><em>23.19.3 [execpol.type],
      28.4.3 [algorithms.parallel.exec]</em></span>
      There are no implementation-defined execution policies.
   </p><p>
      <span class="emphasis"><em>24.4.2 [string.view.template]</em></span>
      <code class="classname">basic_string_view&lt;C, T&gt;::iterator</code> is
      <code class="code">C*</code> and
      <code class="classname">basic_string_view&lt;C, T&gt;::const_iterator</code> is
      <code class="code">const C*</code>.
   </p><p>
      <span class="emphasis"><em>28.4.3 [algorithms.parallel.exec]</em></span>
      Threads of execution created by <code class="classname">std::thread</code>
      provide concurrent forward progress guarantees, so threads of execution
      implicitly created by the library will provide parallel forward
      progress guarantees.
   </p><p>
      <span class="emphasis"><em>29.4.1 [cfenv.syn]</em></span>
      The effects of the <code class="filename">&lt;cfenv&gt;</code> functions
      depends on whether the <code class="code">FENV_ACCESS</code> pragma is supported,
      and on the C library that provides the header.
   </p><p>
      <span class="emphasis"><em>29.6.9 [c.math.rand]</em></span>
      Whether the <code class="function">rand</code> function may introduce data
      races depends on the target C library that provides the function.
   </p><p>
      <span class="emphasis"><em>29.9.5 [sf.cmath]</em></span>
      The effect of calling the mathematical special functions with large
      inputs should be documented here.
   </p><p>
      <span class="emphasis"><em>30.10.2.1 [fs.conform.9945]</em></span>
      The behavior of the filesystem library implementation will depend on
      the target operating system. Some features will not be supported
      on some targets. Symbolic links and file permissions
      are not supported on Windows.
   </p><p>
      <span class="emphasis"><em>30.10.5 [fs.filesystem.syn]</em></span>
      The clock used for file times is an unspecified type
      with a signed 64-bit representation, capable of representing
      timestamps with nanosecond resolution. The clock's epoch is
      unspecified, but is not the same as the system clock's epoch.
   </p><p>
      <span class="emphasis"><em>30.10.7.1 [fs.path.generic]</em></span>
      dot-dot in the root-directory refers to the root-directory itself.
      On Windows, a drive specifier such as <code class="code">"C:"</code> or
      <code class="code">"z:"</code> is treated as a root-name. On Cygwin, a path
      that begins with two successive directory separators is a
      root-name. Otherwise (for POSIX-like systems other than Cygwin),
      the implementation-defined root-name is an unspecified string
      which does not appear in any pathnames.
   </p><p>
      <span class="emphasis"><em>30.10.10.1 [fs.enum.path.format]</em></span>
      The character sequence is always interpreted in the native pathname
      format.
   </p><p>
      <span class="emphasis"><em>30.10.15.4 [fs.op.file_size]</em></span>
      If <code class="code">!is_regular_file(p)</code>, an error is reported.
   </p><p>
      <span class="emphasis"><em>30.10.15.32 [fs.op.rename]</em></span>
      On Windows, <code class="code">filesystem::rename</code>
      is implemented by calling <code class="code">MoveFileExW</code> and so
      does not meet the requirements of POSIX <code class="code">rename</code>
      when one or both of the paths resolves to an existing directory.
      Specifically, it is not possible to rename a directory to replace another
      directory (POSIX requires that to work if the directory being
      replaced is empty).
    </p><div class="section"><div class="titlepage"><div><div><h5 class="title"><a id="iso.2017.par2ts"></a>Parallelism 2 TS</h5></div></div></div><p>
        <span class="emphasis"><em>9.3 [parallel.simd.abi]</em></span>
        <code class="code">max_fixed_size&lt;T&gt;</code> is 32, except when targetting
        AVX512BW and <code class="code">sizeof(T)</code> is 1.
     </p><p>
        When targeting 32-bit x86,
        <code class="classname">simd_abi::compatible&lt;T&gt;</code> is an alias for
        <code class="classname">simd_abi::scalar</code>.
        When targeting 64-bit x86 (including x32) or Aarch64,
        <code class="classname">simd_abi::compatible&lt;T&gt;</code> is an alias for
        <code class="classname">simd_abi::_VecBuiltin&lt;16&gt;</code>,
        unless <code class="code">T</code> is <code class="code">long double</code>, in which case it is
        an alias for <code class="classname">simd_abi::scalar</code>.
        When targeting ARM (but not Aarch64) with NEON support,
        <code class="classname">simd_abi::compatible&lt;T&gt;</code> is an alias for
        <code class="classname">simd_abi::_VecBuiltin&lt;16&gt;</code>,
        unless <code class="code">sizeof(T) &gt; 4</code>, in which case it is
        an alias for <code class="classname">simd_abi::scalar</code>. Additionally,
        <code class="classname">simd_abi::compatible&lt;float&gt;</code> is an alias for
        <code class="classname">simd_abi::scalar</code> unless compiling with
        -ffast-math.
     </p><p>
        When targeting x86 (both 32-bit and 64-bit),
        <code class="classname">simd_abi::native&lt;T&gt;</code> is an alias for one of
        <code class="classname">simd_abi::scalar</code>,
        <code class="classname">simd_abi::_VecBuiltin&lt;16&gt;</code>,
        <code class="classname">simd_abi::_VecBuiltin&lt;32&gt;</code>, or
        <code class="classname">simd_abi::_VecBltnBtmsk&lt;64&gt;</code>, depending on
        <code class="code">T</code> and the machine options the compiler was invoked with.
     </p><p>
        When targeting ARM/Aarch64 or POWER,
        <code class="classname">simd_abi::native&lt;T&gt;</code> is an alias for
        <code class="classname">simd_abi::scalar</code> or
        <code class="classname">simd_abi::_VecBuiltin&lt;16&gt;</code>, depending on
        <code class="code">T</code> and the machine options the compiler was invoked with.
     </p><p>
        For any other targeted machine
        <code class="classname">simd_abi::compatible&lt;T&gt;</code> and
        <code class="classname">simd_abi::native&lt;T&gt;</code> are aliases for
        <code class="classname">simd_abi::scalar</code>. (subject to change)
     </p><p>
        The extended ABI tag types defined in the
        <code class="code">std::experimental::parallelism_v2::simd_abi</code> namespace are:
        <code class="classname">simd_abi::_VecBuiltin&lt;Bytes&gt;</code>, and
        <code class="classname">simd_abi::_VecBltnBtmsk&lt;Bytes&gt;</code>.
     </p><p>
        <code class="classname">simd_abi::deduce&lt;T, N, Abis...&gt;::type</code>,
        with <code class="code">N &gt; 1</code> is an alias for an extended ABI tag, if a
        supported extended ABI tag exists. Otherwise it is an alias for
        <code class="classname">simd_abi::fixed_size&lt;N&gt;</code>. The <code class="classname">
        simd_abi::_VecBltnBtmsk</code> ABI tag is preferred over
        <code class="classname">simd_abi::_VecBuiltin</code>.
     </p><p>
        <span class="emphasis"><em>9.4 [parallel.simd.traits]</em></span>
        <code class="classname">memory_alignment&lt;T, U&gt;::value</code> is
        <code class="code">sizeof(U) * T::size()</code> rounded up to the next power-of-two
        value.
     </p><p>
        <span class="emphasis"><em>9.6.1 [parallel.simd.overview]</em></span>
        On ARM, <code class="classname">simd&lt;T, _VecBuiltin&lt;Bytes&gt;&gt;</code>
        is supported if <code class="code">__ARM_NEON</code> is defined and
        <code class="code">sizeof(T) &lt;= 4</code>. Additionally,
        <code class="code">sizeof(T) == 8</code> with integral <code class="code">T</code> is supported if
        <code class="code">__ARM_ARCH &gt;= 8</code>, and <code class="code">double</code> is supported if
        <code class="code">__aarch64__</code> is defined.

        On POWER, <code class="classname">simd&lt;T, _VecBuiltin&lt;Bytes&gt;&gt;</code>
        is supported if <code class="code">__ALTIVEC__</code> is defined and <code class="code">sizeof(T)
        &lt; 8</code>. Additionally, <code class="code">double</code> is supported if
        <code class="code">__VSX__</code> is defined, and any <code class="code">T</code> with <code class="code">
        sizeof(T) &lt;= 8</code> is supported if <code class="code">__POWER8_VECTOR__</code>
        is defined.

        On x86, given an extended ABI tag <code class="code">Abi</code>,
        <code class="classname">simd&lt;T, Abi&gt;</code> is supported according to the
        following table:
        </p><div class="table"><a id="table.par2ts_simd_support"></a><p class="title"><strong>Table 1.8. Support for Extended ABI Tags</strong></p><div class="table-contents"><table class="table" summary="Support for Extended ABI Tags" border="1"><colgroup><col align="left" class="c1" /><col align="left" class="c2" /><col align="left" class="c3" /><col align="left" class="c4" /></colgroup><thead><tr><th align="left">ABI tag <code class="code">Abi</code></th><th align="left">value type <code class="code">T</code></th><th align="left">values for <code class="code">Bytes</code></th><th align="left">required machine option</th></tr></thead><tbody><tr><td rowspan="6" align="left">
                  <code class="classname">_VecBuiltin&lt;Bytes&gt;</code>
                </td><td rowspan="2" align="left"><code class="code">float</code></td><td align="left">8, 12, 16</td><td align="left">"-msse"</td></tr><tr><td align="left">20, 24, 28, 32</td><td align="left">"-mavx"</td></tr><tr><td rowspan="2" align="left"><code class="code">double</code></td><td align="left">16</td><td align="left">"-msse2"</td></tr><tr><td align="left">24, 32</td><td align="left">"-mavx"</td></tr><tr><td rowspan="2" align="left">
                  integral types other than <code class="code">bool</code>
                </td><td align="left">
                  <code class="code">Bytes</code> ≤ 16 and <code class="code">Bytes</code> divisible by
                  <code class="code">sizeof(T)</code>
                </td><td align="left">"-msse2"</td></tr><tr><td align="left">
                  16 &lt; <code class="code">Bytes</code> ≤ 32 and <code class="code">Bytes</code>
                  divisible by <code class="code">sizeof(T)</code>
                </td><td align="left">"-mavx2"</td></tr><tr><td rowspan="2" align="left">
                  <code class="classname">_VecBuiltin&lt;Bytes&gt;</code> and
                  <code class="classname">_VecBltnBtmsk&lt;Bytes&gt;</code>
                </td><td align="left">
                  vectorizable types with <code class="code">sizeof(T)</code> ≥ 4
                </td><td rowspan="2" align="left">
                  32 &lt; <code class="code">Bytes</code> ≤ 64 and <code class="code">Bytes</code>
                  divisible by <code class="code">sizeof(T)</code>
                </td><td align="left">"-mavx512f"</td></tr><tr><td align="left">
                  vectorizable types with <code class="code">sizeof(T)</code> &lt; 4
                </td><td align="left">"-mavx512bw"</td></tr><tr><td rowspan="2" align="left">
                  <code class="classname">_VecBltnBtmsk&lt;Bytes&gt;</code>
                </td><td align="left">
                  vectorizable types with <code class="code">sizeof(T)</code> ≥ 4
                </td><td rowspan="2" align="left">
                  <code class="code">Bytes</code> ≤ 32 and <code class="code">Bytes</code> divisible by
                  <code class="code">sizeof(T)</code>
                </td><td align="left">"-mavx512vl"</td></tr><tr><td align="left">
                  vectorizable types with <code class="code">sizeof(T)</code> &lt; 4
                </td><td align="left">"-mavx512bw" and "-mavx512vl"</td></tr></tbody></table></div></div><p><br class="table-break" />
     </p></div></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="status.iso.2020"></a>C++ 2020</h3></div></div></div><p>
In this implementation the <code class="literal">-std=gnu++20</code> or
<code class="literal">-std=c++20</code> flag must be used to enable language
and library
features. See <a class="link" href="using.html#manual.intro.using.flags" title="Command Options">dialect</a>
options. The pre-defined symbol
<code class="constant">__cplusplus</code> is used to check for the
presence of the required flag.
</p><p>
This section describes the C++20 and library TS support in mainline GCC,
not in any particular release.
</p><p>
The following table lists new library features that are included in
the C++20 standard. The "Proposal" column provides a link to the
ISO C++ committee proposal that describes the feature, while the "Status"
column indicates the first version of GCC that contains an implementation of
this feature (if it has been implemented).
A dash (—) in the status column indicates that the changes in the proposal
either do not affect the code in libstdc++, or the changes are not required for conformance.
The "SD-6 Feature Test / Notes" column shows the corresponding macro or header from
<a class="link" href="https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations" target="_top">SD-6:
Feature-testing recommendations for C++</a> (where applicable)
or any notes about the implementation.
</p><div class="table"><a id="table.cxx20_features"></a><p class="title"><strong>Table 1.9. C++ 2020 Library Features</strong></p><div class="table-contents"><table class="table" summary="C++ 2020 Library Features" border="1"><colgroup><col align="left" class="c1" /><col align="left" class="c2" /><col align="left" class="c3" /><col align="left" class="c4" /></colgroup><thead><tr><th align="left">Library Feature</th><th align="left">Proposal</th><th align="left">Status</th><th align="left">SD-6 Feature Test / Notes</th></tr></thead><tbody><tr><td colspan="4" align="left">
        <span class="bold"><strong>Compile-time programming</strong></span>
      </td></tr><tr><td align="left">  Add constexpr modifiers to functions in <code class="code">&lt;algorithm&gt;</code> and <code class="code">&lt;utility&gt;</code> Headers </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0202r3.html" target="_top">
        P0202R3 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_constexpr_algorithms &gt;= 201703L</code> </td></tr><tr><td align="left">  Constexpr for <code class="code">swap</code> and swap related functions </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0879r0.html" target="_top">
        P0879R0 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_constexpr_algorithms &gt;= 201806L</code> </td></tr><tr><td align="left">  Constexpr for <code class="code">std::complex</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0415r1.html" target="_top">
        P0415R1 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_constexpr_complex &gt;= 201711L</code> (since 9.4, see Note 1) </td></tr><tr><td align="left">  <code class="code">std::is_constant_evaluated()</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0595r2.html" target="_top">
        P0595R2 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_is_constant_evaluated &gt;= 201811L</code> </td></tr><tr><td align="left">  More constexpr containers </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0784r7.html" target="_top">
        P0784R7 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_constexpr_dynamic_alloc &gt;= 201907L</code> </td></tr><tr><td align="left">  Making <code class="code">std::string</code> constexpr </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0980r1.pdf" target="_top">
        P0980R1 </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_constexpr_string &gt;= 201907L</code> </td></tr><tr><td align="left">  Making <code class="code">std::vector</code> constexpr </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1004r2.pdf" target="_top">
        P1004R2 </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_constexpr_vector &gt;= 201907L</code> </td></tr><tr><td align="left">  Constexpr in <code class="code">std::pointer_traits</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1006r1.pdf" target="_top">
        P1006R1 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_constexpr_memory &gt;= 201811L</code> (since 9.4, see Note 1) </td></tr><tr><td align="left">  constexpr for <code class="code">&lt;numeric&gt;</code> algorithms </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1645r1.html" target="_top">
        P1645R1 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_constexpr_numeric &gt;= 201911L</code> </td></tr><tr><td align="left">  Constexpr iterator requirements </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0858r0.html" target="_top">
        P0858R0 </a>
      </td><td align="center"> 9.1 </td><td align="left">
        <div class="informaltable"><table class="informaltable" border="0"><colgroup><col /></colgroup><tbody><tr><td> <code class="code">__cpp_lib_array_constexpr &gt;= 201803L</code> </td></tr><tr><td> <code class="code">__cpp_lib_string_view &gt;= 201803L</code> </td></tr><tr><td> (both since 9.4, see Note 1) </td></tr></tbody></table></div>
      </td></tr><tr><td align="left">  <code class="code">constexpr</code> comparison operators for <code class="code">std::array</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1023r0.pdf" target="_top">
        P1023R0 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_array_constexpr &gt;= 201806</code> </td></tr><tr><td align="left">  Misc constexpr bits </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1032r1.html" target="_top">
        P1032R1 </a>
      </td><td align="center"> 10.1 </td><td align="left">
        <div class="informaltable"><table class="informaltable" border="0"><colgroup><col /></colgroup><tbody><tr><td> <code class="code">__cpp_lib_array_constexpr &gt;= 201811L</code> </td></tr><tr><td> <code class="code">__cpp_lib_constexpr_functional &gt;= 201811L</code> </td></tr><tr><td> <code class="code">__cpp_lib_constexpr_iterator &gt;= 201811L</code> </td></tr><tr><td> <code class="code">__cpp_lib_constexpr_string_view &gt;= 201811L</code> </td></tr><tr><td> <code class="code">__cpp_lib_constexpr_tuple &gt;= 201811L</code> </td></tr><tr><td> <code class="code">__cpp_lib_constexpr_utility &gt;= 201811L</code> </td></tr></tbody></table></div>
      </td></tr><tr><td align="left">  <code class="code">constexpr <span class="emphasis"><em>INVOKE</em></span></code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1065r2.html" target="_top">
        P1065R2 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_constexpr_functional &gt;= 201907L</code> </td></tr><tr><td align="left">  Transformation Trait <code class="code">remove_cvref</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0550r2.pdf" target="_top">
        P0550R2 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_remove_cvref &gt;= 201711L</code> (since 9.4, see Note 1) </td></tr><tr><td align="left">  Implicit conversion traits and utility functions </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0758r1.html" target="_top">
        P0758R1 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_is_nothrow_convertible &gt;= 201806L</code>  (since 9.4, see Note 1) </td></tr><tr><td align="left">  The <code class="code">identity</code> metafunction </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0887r1.pdf" target="_top">
        P0887R1 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_type_identity &gt;= 201806L</code> (since 9.4, see Note 1) </td></tr><tr><td align="left">  <code class="code">unwrap_ref_decay</code> and <code class="code">unwrap_reference</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0318r1.pdf" target="_top">
        P0318R1 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_unwrap_ref &gt;= 201811L</code> (since 9.4, see Note 1) </td></tr><tr bgcolor="#B0B0B0"><td align="left">  Improving Completeness Requirements for Type Traits </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1285r0.pdf" target="_top">
        P1285R0 </a>
      </td><td align="center"> Partial </td><td align="left"> </td></tr><tr><td align="left">  Missing feature test macros </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1353r0.html" target="_top">
        P1353R0 </a>
      </td><td align="center"> 9.1 </td><td align="left"> </td></tr><tr><td align="left"> Making std::underlying_type SFINAE-friendly </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0340r3.html" target="_top">
        P0340R3 </a>
      </td><td align="center"> 9.1 </td><td align="left"> </td></tr><tr><td align="left"> Traits for [Un]bounded Arrays </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1357r1.pdf" target="_top">
        P1357R1 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_bounded_array_traits &gt;= 201902L</code> </td></tr><tr><td align="left"> Layout-compatibility and pointer-interconvertibility traits </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0466r5.pdf" target="_top">
        P0466R5 </a>
      </td><td align="center"> 12.1 </td><td align="left">
        <div class="informaltable"><table class="informaltable" border="0"><colgroup><col /></colgroup><tbody><tr><td> <code class="code">__cpp_lib_is_layout_compatible &gt;= 201907L</code> </td></tr><tr><td> <code class="code">__cpp_lib_is_pointer_interconvertible &gt;= 201907L</code> </td></tr></tbody></table></div>
      </td></tr><tr><td align="left">  Integrating feature-test macros into the C++ WD </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0941r2.html" target="_top">
        P0941R2 </a>
      </td><td align="center"> 5.1 </td><td align="left"> </td></tr><tr><td align="left">  <code class="code">&lt;version&gt;</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0754r2.pdf" target="_top">
        P0754R2 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__has_include(&lt;version&gt;)</code> </td></tr><tr><td colspan="4" align="left">
        <span class="bold"><strong>Synchronization</strong></span>
      </td></tr><tr><td align="left">  Atomic Ref </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0019r8.html" target="_top">
        P0019R8 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_atomic_ref &gt;= 201806L</code> </td></tr><tr><td align="left">  Floating Point Atomic </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0020r6.html" target="_top">
        P0020R6 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_atomic_float &gt;= 201711L</code> </td></tr><tr><td align="left">  C++ Synchronized Buffered Ostream </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0053r7.pdf" target="_top">
        P0053R7 </a>
      </td><td align="center"> 11.1 </td><td align="left"> <code class="code">__cpp_lib_syncbuf &gt;= 201711L</code> </td></tr><tr><td align="left">  Manipulators for C++ Synchronized Buffered Ostream </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0753r2.pdf" target="_top">
        P0753R2 </a>
      </td><td align="center"> 11.1 </td><td align="left"> <code class="code">__cpp_lib_syncbuf &gt;= 201803L</code> </td></tr><tr><td align="left">  Make <code class="code">std::memory_order</code> a scoped enumeration </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0439r0.html" target="_top">
        P0439R0 </a>
      </td><td align="center"> 9.1 </td><td align="left"> </td></tr><tr><td align="left">  The Curious Case of Padding Bits, Featuring Atomic Compare-and-Exchange </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0528r3.html" target="_top">
        P0528R3 </a>
      </td><td align="center"> 13.1 </td><td align="left"> </td></tr><tr><td align="left">  Atomic <code class="code">shared_ptr</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0718r2.html" target="_top">
        P0718R2 </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code"> __cpp_lib_atomic_shared_ptr &gt;= 201711L</code> </td></tr><tr><td align="left"> std::stop_token and std::jthread </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0660r10.pdf" target="_top">
        P0660R10 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_jthread &gt;= 201907L</code> </td></tr><tr><td align="left"> Rename <code class="code">condition_variable_any</code> interruptible wait methods </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1869r1.html" target="_top">
        P1869R1 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_jthread &gt;= 201911L</code> </td></tr><tr><td align="left"> Atomic waiting and notifying, std::semaphore, std::latch and std::barrier </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1135r6.html" target="_top">
        P1135R6 </a>
      </td><td align="center"> 11.1 </td><td align="left">
        <div class="informaltable"><table class="informaltable" border="0"><colgroup><col /></colgroup><tbody><tr><td> <code class="code">__cpp_lib_atomic_lock_free_type_aliases &gt;= 201907L</code> </td></tr><tr><td> <code class="code">__cpp_lib_atomic_flag_test &gt;= 201907L</code> </td></tr><tr><td> <code class="code">__cpp_lib_atomic_wait &gt;= 201907L</code> </td></tr><tr><td> <code class="code">__cpp_lib_semaphore &gt;= 201907L</code> </td></tr><tr><td> <code class="code">__cpp_lib_latch &gt;= 201907L</code> </td></tr><tr><td> <code class="code">__cpp_lib_barrier &gt;= 201907L</code> </td></tr></tbody></table></div>
      </td></tr><tr><td align="left"> Fixing Atomic Initialization </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0883r2.pdf" target="_top">
        P0883R2 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_atomic_value_initialization &gt;= 201911L</code> </td></tr><tr><td colspan="4" align="left">
        <span class="bold"><strong>Ranges and Concepts</strong></span>
      </td></tr><tr><td align="left">  Standard Library Concepts </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0898r3.pdf" target="_top">
        P0898R3 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_concepts &gt;= 201806L</code> </td></tr><tr><td align="left">  Rename concepts to standard_case for C++20, while we still can </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1754r1.pdf" target="_top">
        P1754R1 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_concepts &gt;= 201907L</code> </td></tr><tr><td align="left">  Wording for <span class="emphasis"><em><code class="code">boolean-testable</code></em></span> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p1964r2.html" target="_top">
        P1964R2 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_concepts &gt;= 202002L</code> </td></tr><tr><td align="left">  The One Ranges Proposal </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0896r4.pdf" target="_top">
        P0896R4 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_ranges &gt;= 201811L</code> </td></tr><tr><td align="left">  Input Range Adaptors </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1035r7.pdf" target="_top">
        P1035R7 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_ranges &gt;= 201907L</code> </td></tr><tr><td align="left">  <code class="code">ranges</code> compare algorithm are over-constrained </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1716r3.html" target="_top">
        P1716R3 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_ranges &gt;= 201911L</code> </td></tr><tr><td align="left">  Remove CommonReference requirement from StrictWeakOrdering (a.k.a Fixing Relations) </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1248r1.html" target="_top">
        P1248R1 </a>
      </td><td align="center"> 10.1 </td><td align="left"> </td></tr><tr><td align="left"> Ranges Design Cleanup </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1252r2.pdf" target="_top">
        P1252R2 </a>
      </td><td align="center"> 10.1 </td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left"> Avoid template bloat for <code class="code">safe_ranges</code> in combination with ‘subrange-y’ view adaptors.</td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p1739r4.html" target="_top">
        P1739R4 </a>
      </td><td align="center"> </td><td align="left"> </td></tr><tr><td colspan="4" align="left">
        <span class="bold"><strong>Time, dates, calendars, time zones</strong></span>
      </td></tr><tr bgcolor="#C8B0B0"><td align="left">  Extending chrono to Calendars and Time Zones </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0355r7.html" target="_top">
        P0355R7 </a>
      </td><td align="left"> </td><td align="left"> <code class="code">__cpp_lib_chrono &gt;= 201803L</code> </td></tr><tr bgcolor="#C8B0B0"><td align="left"> Miscellaneous minor fixes for chrono </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1466r3.html" target="_top">
        P1466R3 </a>
      </td><td align="left"> </td><td align="left"> <code class="code">__cpp_lib_chrono &gt;= 201907L</code> </td></tr><tr><td align="left">  <code class="code">&lt;chrono&gt;</code> <code class="code">zero()</code>, <code class="code">min()</code>, and <code class="code">max()</code> should be <code class="code">noexcept</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0972r0.pdf" target="_top">
        P0972R0 </a>
      </td><td align="center"> 9.1 </td><td align="left"> </td></tr><tr><td colspan="4" align="left">
        <span class="bold"><strong>Three-way comparison</strong></span>
      </td></tr><tr><td align="left">  Library Support for the Spaceship (Comparison) Operator </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0768r1.pdf" target="_top">
        P0768R1 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_three_way_comparison &gt;= 201711L</code> </td></tr><tr><td align="left">  Symmetry for spaceship </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0905r1.html" target="_top">
        P0905R1 </a>
      </td><td align="center"> 10.1 </td><td align="left"> </td></tr><tr><td align="left"> Adding &lt;=&gt; to the standard library </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1614r2.html" target="_top">
        P1614R2 </a>
      </td><td align="center"> 10.1 </td><td align="left">
        <code class="code">__cpp_lib_three_way_comparison &gt;= 201907L</code>
      </td></tr><tr><td colspan="4" align="left">
        <span class="bold"><strong>Strings and text</strong></span>
      </td></tr><tr><td align="left">  <code class="code">string::reserve</code> Should Not Shrink </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0966r1.html" target="_top">
        P0966R1 </a>
      </td><td align="center"> 11.1 </td><td align="left"> </td></tr><tr><td align="left">  <code class="code">char8_t</code>: A type for UTF-8 characters and strings </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0482r6.html" target="_top">
        P0482R6 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_char8_t &gt;= 201811L</code> </td></tr><tr><td align="left">  <code class="code">char8_t</code> backward compatibility remediation </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1423r3.html" target="_top">
        P1423R3 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_char8_t &gt;= 201907L</code> </td></tr><tr bgcolor="#C8B0B0"><td align="left"> Text formatting </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0645r10.html" target="_top">
        P0645R10 </a>
      </td><td align="center"> </td><td align="left">
        <code class="code">__cpp_lib_format &gt;= 201907L</code>
      </td></tr><tr bgcolor="#C8B0B0"><td align="left"> Integration of chrono with text formatting </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1361r2.pdf" target="_top">
        P1361R2 </a>
      </td><td align="center"> </td><td align="left">
        <code class="code">__cpp_lib_format &gt;= 201907L</code>
      </td></tr><tr bgcolor="#C8B0B0"><td align="left"> Printf corner cases in <code class="code">std::format</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1652r1.html" target="_top">
        P1652R1 </a>
      </td><td align="center"> </td><td align="left">
        <code class="code">__cpp_lib_format &gt;= 201907L</code>
      </td></tr><tr><td align="left">  String Prefix and Suffix Checking </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0457r2.html" target="_top">
        P0457R2 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_starts_ends_with &gt;= 201711L</code> (since 9.4, see Note 1) </td></tr><tr bgcolor="#C8B0B0"><td align="left">  Update The Reference To The Unicode Standard </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1025r1.html" target="_top">
        P1025R1 </a>
      </td><td align="center"> </td><td align="left"> </td></tr><tr><td colspan="4" align="left">
        <span class="bold"><strong>Containers</strong></span>
      </td></tr><tr><td align="left"> span: bounds-safe views for sequences of objects </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0122r7.pdf" target="_top">
        P0122R7 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_span &gt;= 201803L</code> </td></tr><tr><td align="left">
        Usability Enhancements for <code class="classname">std::span</code>
      </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1024r3.pdf" target="_top">
        P1024R3 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_span &gt;= 201902L</code> </td></tr><tr><td align="left">  Should Span be Regular? </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1085r2.md" target="_top">
        P1085R2 </a>
      </td><td align="center"> 10.1 </td><td align="left"> </td></tr><tr><td align="left"> Fixed-size <code class="code">&lt;span&gt;</code> construction from dynamic range </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p1976r2.html" target="_top">
        P1976R2 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_span &gt;= 202002L</code> </td></tr><tr><td align="left"> <code class="code">std::to_array</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0325r4.html" target="_top">
        P0325R4 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_to_array &gt;= 201907L</code> </td></tr><tr><td align="left">  Checking for Existence of an Element in Associative Containers </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0458r2.html" target="_top">
        P0458R2 </a>
      </td><td align="center"> 9.1 </td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">  Comparing Unordered Containers </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0809r0.pdf" target="_top">
        P0809R0 </a>
      </td><td align="center"> </td><td align="left"> </td></tr><tr><td align="left">  Heterogeneous lookup for unordered containers </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0919r3.html" target="_top">
        P0919R3 </a>
      </td><td align="center"> 11.1 </td><td align="left"> <code class="code">__cpp_lib_generic_unordered_lookup &gt;= 201811</code> </td></tr><tr><td align="left"> Refinement Proposal for P0919 </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1690r1.html" target="_top">
        P1690R1 </a>
      </td><td align="center"> 11.1 </td><td align="left"> </td></tr><tr><td align="left">  Adopt Consistent Container Erasure from Library Fundamentals 2 for C++20 </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1209r0.html" target="_top">
        P1209R0 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_erase_if &gt;= 201811L</code> </td></tr><tr><td align="left">  Improving the Return Value of Erase-Like Algorithms </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0646r1.pdf" target="_top">
        P0646R1 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_list_remove_return_type &gt;= 201806L</code> </td></tr><tr><td align="left">  Improving the Return Value of Erase-Like Algorithms II: Free <code class="code">erase</code>/<code class="code">erase_if</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1115r3.pdf" target="_top">
        P1115R3 </a>
      </td><td align="center"> 9.1 </td><td align="left">
        <div class="informaltable"><table class="informaltable" border="0"><colgroup><col /></colgroup><tbody><tr><td> <code class="code">__cpp_lib_erase_if &gt;= 202002L</code> </td></tr><tr><td> (defined to <code class="code">201900L</code> for GCC 9.1 and 9.2 so use <code class="code">&gt; 201811L</code>) </td></tr></tbody></table></div>
      </td></tr><tr><td align="left"> Signed ssize() functions, unsigned size() functions </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1227r2.html" target="_top">
        P1227R2 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_ssize &gt;= 201902L</code> </td></tr><tr><td colspan="4" align="left">
        <span class="bold"><strong>Memory management</strong></span>
      </td></tr><tr><td align="left">  Utility to convert a pointer to a raw pointer </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0653r2.html" target="_top">
        P0653R2 </a>
      </td><td align="center"> 8.1 </td><td align="left"> <code class="code">__cpp_lib_to_address &gt;= 201711L</code> (since 9.4, see Note 1) </td></tr><tr><td align="left">  Extending <code class="code">make_shared</code> to Support Arrays </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0674r1.html" target="_top">
        P0674R1 </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_shared_ptr_arrays &gt;= 201707L</code> </td></tr><tr><td align="left">  Efficient sized delete for variable sized classes </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0722r3.html" target="_top">
        P0722R3 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_destroying_delete &gt;= 201806L</code> </td></tr><tr><td align="left">  Utility functions to implement uses-allocator construction </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0591r4.pdf" target="_top">
        P0591R4 </a>
      </td><td align="center"> 9.1 </td><td align="left">
        <code class="code">std::scoped_allocator_adaptor</code> changes missing in 9.1.0
      </td></tr><tr><td align="left">  <code class="code">std::assume_aligned</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1007r3.pdf" target="_top">
        P1007R3 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_assume_aligned &gt;= 201811L</code> (since 9.4, see Note 1) </td></tr><tr><td align="left">  Smart pointer creation with default initialization </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1020r1.html" target="_top">
        P1020R1 </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_smart_ptr_for_overwrite &gt;= 201811L</code> </td></tr><tr><td align="left">  Rename "default_init" Functions </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p1973r1.pdf" target="_top">
        P1973R1 </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_smart_ptr_for_overwrite &gt;= 201811L</code> </td></tr><tr><td align="left">  Make stateful allocator propagation more consistent for <code class="code">operator+(basic_string)</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1165r1.html" target="_top">
        P1165R1 </a>
      </td><td align="center"> 10.1 </td><td align="left"> </td></tr><tr><td align="left">
        <code class="classname">polymorphic_allocator&lt;&gt;</code> as a vocabulary type
      </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0339r6.pdf" target="_top">
        P0339R6 </a>
      </td><td align="center"> 9.1 </td><td align="left">
      <code class="code">__cpp_lib_polymorphic_allocator &gt;= 201902L</code> (since 9.4, see Note 1)
      </td></tr><tr><td align="left">  LWG 2511: guaranteed copy elision for piecewise construction </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0475r1.html" target="_top">
        P0475R1 </a>
      </td><td align="center"> 7.1 </td><td align="left"> </td></tr><tr><td colspan="4" align="left">
        <span class="bold"><strong>Miscellaneous</strong></span>
      </td></tr><tr><td align="left">  <code class="code">nodiscard</code> in the Library </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0600r1.pdf" target="_top">
        P0600R1 </a>
      </td><td align="center"> 9.1 </td><td align="left"> </td></tr><tr><td align="left">  de-pessimize legacy algorithms with <code class="code">std::move</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0616r0.pdf" target="_top">
        P0616R0 </a>
      </td><td align="center"> 9.1 </td><td align="left"> </td></tr><tr><td align="left">  Deprecate POD </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0767r1.html" target="_top">
        P0767R1 </a>
      </td><td align="center"> 10.1 </td><td align="left"> </td></tr><tr><td align="left">  Treating Unnecessary <code class="code">decay</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0777r1.pdf" target="_top">
        P0777R1 </a>
      </td><td align="center"> 9.1 </td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">  Thou Shalt Not Specialize std Function Templates! </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0551r3.pdf" target="_top">
        P0551R3 </a>
      </td><td align="center"> </td><td align="left"> </td></tr><tr><td align="left">  Bit-casting object representations </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0476r2.html" target="_top">
        P0476R2 </a>
      </td><td align="center"> 11.1 </td><td align="left"> <code class="code">__cpp_lib_bit_cast &gt;= 201806L</code> </td></tr><tr><td align="left">  Integral power-of-2 operations </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0556r3.html" target="_top">
        P0556R3 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_int_pow2 &gt;= 201806L</code> (since 9.4, see Note 1) </td></tr><tr><td align="left"> On the names of low-level bit manipulation functions </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p1956r1.pdf" target="_top">
        P1956R1 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_int_pow2 &gt;= 202002L</code> </td></tr><tr><td align="left"> Safe integral comparisons </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p0586r2.html" target="_top">
        P0586R2 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_integer_comparison_functions &gt;= 202002L</code> </td></tr><tr><td align="left">  Reviewing Deprecated Facilities of C++17 for C++20 </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0619r4.html" target="_top">
        P0619R4 </a>
      </td><td align="center"> 12.1 </td><td align="left"> </td></tr><tr><td align="left">  <code class="code">fpos</code> Requirements </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0759r1.html" target="_top">
        P0759R1 </a>
      </td><td align="center"> — </td><td align="left"> </td></tr><tr><td align="left">  Add <code class="code">shift</code> to <code class="code">&lt;algorithm&gt;</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0769r2.pdf" target="_top">
        P0769R2 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_shift &gt;= 201806L</code> </td></tr><tr bgcolor="#C8B0B0"><td align="left">  Standard Library Specification in a Concepts and Contracts World </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0788r3.pdf" target="_top">
        P0788R3 </a>
      </td><td align="center"> </td><td align="left"> </td></tr><tr><td align="left">  <code class="code">explicit(bool)</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0892r2.html" target="_top">
        P0892R2 </a>
      </td><td align="center"> — </td><td align="left"> </td></tr><tr><td align="left">  Eradicating unnecessarily explicit default constructors from the standard library </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0935r0.html" target="_top">
        P0935R0 </a>
      </td><td align="center"> 9.1 </td><td align="left"> </td></tr><tr><td align="left">  <code class="code">std::function</code> move constructor should be <code class="code">noexcept</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0771r1.pdf" target="_top">
        P0771R1 </a>
      </td><td align="center"> 7.2 </td><td align="left"> </td></tr><tr><td align="left">  Simplified partial function application </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0356r5.html" target="_top">
        P0356R5 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_bind_front &gt;= 201811L</code> </td></tr><tr><td align="left">  <code class="code">bind_front</code> should not unwrap <code class="code">reference_wrapper</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1651r0.html" target="_top">
        P1651R0 </a>
      </td><td align="center"> 9.3 </td><td align="left"> <code class="code">__cpp_lib_bind_front &gt;= 201907L</code> </td></tr><tr><td align="left">  <code class="code">reference_wrapper</code> for incomplete types </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0357r3.html" target="_top">
        P0357R3 </a>
      </td><td align="center"> 9.1 </td><td align="left"> </td></tr><tr><td align="left">  Fixing <code class="code">operator&gt;&gt;(basic_istream&amp;, CharT*)</code> (LWG 2499) </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0487r1.html" target="_top">
        P0487R1 </a>
      </td><td align="center"> 11.1 </td><td align="left"> </td></tr><tr><td align="left">  <code class="code">variant</code> and <code class="code">optional</code> should propagate copy/move triviality </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0602r4.html" target="_top">
        P0602R4 </a>
      </td><td align="center"> 8.3 </td><td align="left"> </td></tr><tr><td align="left">  A sane <code class="code">variant</code> converting constructor </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0608r3.html" target="_top">
        P0608R3 </a>
      </td><td align="center"> 10.1 </td><td align="left"> </td></tr><tr><td align="left">  <code class="code">visit&lt;R&gt;</code>: Explicit Return Type for <code class="code">visit</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0655r1.pdf" target="_top">
        P0655R1 </a>
      </td><td align="center"> 9.1 </td><td align="left"> </td></tr><tr><td align="left">  P0899R1 - LWG 3016 is not a defect </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0899r1.html" target="_top">
        P0899R1 </a>
      </td><td align="center"> 7.1 </td><td align="left"> </td></tr><tr><td align="left">  Editorial Guidance for merging P0019r8 and P0528r3 </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1123r0.html" target="_top">
        P1123R0 </a>
      </td><td align="center"> — </td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">  Cleaning up Clause 20 </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1148r0.pdf" target="_top">
        P1148R0 </a>
      </td><td align="center"> </td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">  Completing the Rebase of Library Fundamentals, Version 3, Working Draft </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1210r0.html" target="_top">
        P1210R0 </a>
      </td><td align="center"> </td><td align="left"> </td></tr><tr><td align="left">  Alternative Wording for P0907R4 Signed Integers are Two's Complement </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1236r1.html" target="_top">
        P1236R1 </a>
      </td><td align="center"> — </td><td align="left"> </td></tr><tr><td align="left">
        I Stream, You Stream, We All Stream for
        <code class="classname">istream_iterator</code>
      </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0738r2.html" target="_top">
        P0738R2 </a>
      </td><td align="center"> 10.1 </td><td align="left"> </td></tr><tr><td align="left">
        Mandating the Standard Library:
        Clause 16 - Language support library
      </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1458r1.pdf" target="_top">
        P1458R1 </a>
      </td><td align="center"> — </td><td align="left"> </td></tr><tr><td align="left">
        Mandating the Standard Library:
        Clause 18 - Diagnostics library
      </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1458r1.pdf" target="_top">
        P1459R1 </a>
      </td><td align="center"> — </td><td align="left"> </td></tr><tr><td align="left">
        Mandating the Standard Library:
        Clause 20 - Strings library
      </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1462r1.html" target="_top">
        P1462R1 </a>
      </td><td align="center"> — </td><td align="left"> </td></tr><tr><td align="left">
        Mandating the Standard Library:
        Clause 21 - Containers library
      </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1463r1.pdf" target="_top">
        P1463R1 </a>
      </td><td align="center"> 10.1 </td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">
        Mandating the Standard Library:
        Clause 22 - Iterators library
      </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1464r1.pdf" target="_top">
        P1464R1 </a>
      </td><td align="center"> </td><td align="left"> </td></tr><tr><td align="left"> Make <code class="code">create_directory()</code> Intuitive </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1164r1.pdf" target="_top">
        P1164R1
  </a>
      </td><td align="center"> 8.3 </td><td align="left"> Treated as a DR for C++17 </td></tr><tr><td align="left">
        Target Vectorization Policies from Parallelism V2 TS to C++20
      </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1001r2.html" target="_top">
        P1001R2 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_execution &gt;= 201902L</code> (since 9.4, see Note 1)</td></tr><tr><td align="left"> Merge Coroutines TS into C++20 working draft </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0912r5.html" target="_top">
        P0912R5 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_coroutines &gt;= 201902L</code> </td></tr><tr><td align="left">  Endian just Endian </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0463r1.html" target="_top">
        P0463R1 </a>
      </td><td align="center"> 8.1 </td><td align="left"> <code class="code">__cpp_lib_endian &gt;= 201907L</code> </td></tr><tr><td align="left"> Bit operations </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0553r4.html" target="_top">
        P0553R4 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_bitops &gt;= 201907L</code> (since 9.4, see Note 1) </td></tr><tr><td align="left">  Well-behaved interpolation for numbers and pointers </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0811r3.html" target="_top">
        P0811R3 </a>
      </td><td align="center"> 9.1 </td><td align="left"> <code class="code">__cpp_lib_interpolate &gt;= 201902L</code> </td></tr><tr><td align="left"> Mathematical constants </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0631r8.pdf" target="_top">
        P0631R8 </a>
      </td><td align="center"> 10.1 </td><td align="left"> <code class="code">__cpp_lib_math_constants &gt;= 201907L</code> </td></tr><tr><td align="left"> std::source_location </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1208r6.pdf" target="_top">
        P1208R6 </a>
      </td><td align="center"> 11.1 </td><td align="left">
        <code class="code">__cpp_lib_source_location &gt;= 201907L</code>
      </td></tr><tr><td align="left"> Efficient access to std::basic_stringbuf's Buffer </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p0408r7.pdf" target="_top">
        P0408R7 </a>
      </td><td align="center"> 11.1 </td><td align="left"> </td></tr></tbody></table></div></div><br class="table-break" /><p>
Note 1: This feature is supported in older releases but the
<code class="code">__cpp_lib</code> macro is not defined to the right value
(or not defined at all) until the version shown in parentheses.
</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="status.iso.2023"></a>C++ 2023</h3></div></div></div><p>
In this implementation the <code class="literal">-std=gnu++23</code> or
<code class="literal">-std=c++23</code> flag must be used to enable language
and library
features. See <a class="link" href="using.html#manual.intro.using.flags" title="Command Options">dialect</a>
options. The pre-defined symbol
<code class="constant">__cplusplus</code> is used to check for the
presence of the required flag.
</p><p>
This section describes the C++23 and library TS support in mainline GCC,
not in any particular release.
</p><p>
The following table lists new library features that have been accepted into
the C++23 working draft. The "Proposal" column provides a link to the
ISO C++ committee proposal that describes the feature, while the "Status"
column indicates the first version of GCC that contains an implementation of
this feature (if it has been implemented).
A dash (—) in the status column indicates that the changes in the proposal
either do not affect the code in libstdc++, or the changes are not required for conformance.
The "SD-6 Feature Test / Notes" column shows the corresponding macro or header from
<a class="link" href="https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations" target="_top">SD-6:
Feature-testing recommendations for C++</a> (where applicable)
or any notes about the implementation.
</p><div class="table"><a id="table.cxx23_features"></a><p class="title"><strong>Table 1.10. C++ 2023 Library Features</strong></p><div class="table-contents"><table class="table" summary="C++ 2023 Library Features" border="1"><colgroup><col align="left" class="c1" /><col align="left" class="c2" /><col align="left" class="c3" /><col align="left" class="c4" /></colgroup><thead><tr><th align="left">Library Feature</th><th align="left">Proposal</th><th align="left">Status</th><th align="left">SD-6 Feature Test / Notes</th></tr></thead><tbody><tr><td colspan="4" align="left">
        <span class="bold"><strong>Ranges and Views</strong></span>
      </td></tr><tr><td align="left"> Range constructor for std::string_view </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p1989r2.pdf" target="_top">
        P1989R2
        </a>
      </td><td align="center"> 11.1 </td><td align="left"> </td></tr><tr><td align="left"> <code class="code">join_view</code> should join all views of ranges </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2328r1.html" target="_top">
        P2328R1
        </a>
      </td><td align="center"> 11.2 </td><td align="left"> </td></tr><tr><td align="left"> Clarifying range adaptor objects </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2281r1.html" target="_top">
        P2281R1
        </a>
      </td><td align="center"> 11.1 </td><td align="left"> </td></tr><tr><td align="left"> Views should not be required to be default constructible </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2325r3.html" target="_top">
        P2325R3
        </a>
      </td><td align="center"> 11.3 </td><td align="left"> <code class="code">__cpp_lib_ranges &gt;= 202106L</code> </td></tr><tr><td align="left"> Conditionally borrowed ranges </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p2017r1.html" target="_top">
        P2017R1
        </a>
      </td><td align="center"> 11.1 </td><td align="left"> </td></tr><tr><td align="left"> Require <code class="code">span</code> &amp; <code class="code">basic_string_view</code> to be Trivially Copyable </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2251r1.pdf" target="_top">
        P2251R1
        </a>
      </td><td align="center"> Yes </td><td align="left"> </td></tr><tr><td align="left"> Repairing input range adaptors and counted_iterator </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2259r1.html" target="_top">
        P2259R1
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> </td></tr><tr><td align="left"> Superior String Splitting </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2210r2.html" target="_top">
        P2210R2
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> </td></tr><tr><td align="left"> What is a <code class="code">view</code>? </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2415r2.html" target="_top">
        P2415R2
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_ranges &gt;= 202110L</code> </td></tr><tr><td align="left"> Fix istream_view </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2432r1.pdf" target="_top">
        P2432R1
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left"> <code class="code">starts_with</code> and <code class="code">ends_with</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p1659r3.html" target="_top">
        P1659R3
        </a>
      </td><td align="center"> </td><td align="left"> <code class="code">__cpp_lib_ranges_starts_ends_with &gt;= 202106L</code> </td></tr><tr bgcolor="#C8B0B0"><td align="left"> <code class="code">zip</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2321r2.html" target="_top">
        P2321R2
        </a>
      </td><td align="center"> </td><td align="left"> <code class="code">__cpp_lib_ranges_zip &gt;= 202110L</code> </td></tr><tr><td colspan="4" align="left">
        <span class="bold"><strong>Compile-time programming</strong></span>
      </td></tr><tr><td align="left"> A proposal for a type trait to detect scoped enumerations </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p1048r1.pdf" target="_top">
        P1048R1
        </a>
      </td><td align="center"> 11.1 </td><td align="left"> <code class="code">__cpp_lib_is_scoped_enum &gt;= 202011L</code> </td></tr><tr><td align="left"> std::to_underlying for enumerations </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p1682r3.html" target="_top">
        P1682R3
        </a>
      </td><td align="center"> 11.1 </td><td align="left"> <code class="code">__cpp_lib_to_underlying &gt;= 202102L</code> </td></tr><tr><td align="left"> Missing constexpr in std::optional and std::variant </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2231r1.html" target="_top">
        P2231R1
        </a>
      </td><td align="center">
	<div class="informaltable"><table class="informaltable" border="0"><colgroup><col /></colgroup><tbody><tr><td> 11.3 (<code class="code">optional</code>) </td></tr><tr><td> 12.1 (<code class="code">variant</code>) </td></tr></tbody></table></div>
      </td><td align="left">
	<div class="informaltable"><table class="informaltable" border="0"><colgroup><col /></colgroup><tbody><tr><td> <code class="code">__cpp_lib_constexpr_optional &gt;= 202106L</code> </td></tr><tr><td> <code class="code">__cpp_lib_variant &gt;= 202106L</code> </td></tr></tbody></table></div>
      </td></tr><tr><td align="left"> Making <code class="code">std::unique_ptr</code> constexpr </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2273r3.pdf" target="_top">
        P2273R3
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_constexpr_memory &gt;= 202202L</code> </td></tr><tr><td align="left"> Making <code class="code">std::type_info::operator==</code> constexpr </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p1328r1.html" target="_top">
        P1328R1
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_constexpr_typeinfo &gt;= 202106L</code> </td></tr><tr bgcolor="#C8B0B0"><td align="left"> constexpr for <code class="code">&lt;cmath&gt;</code> and <code class="code">&lt;cstdlib&gt;</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p0533r9.pdf" target="_top">
        P0533R9
        </a>
      </td><td align="center"> </td><td align="left"> <code class="code">__cpp_lib_constexpr_cmath &gt;= 202202L</code> </td></tr><tr bgcolor="#C8B0B0"><td align="left"> Deprecate std::aligned_storage and std::aligned_union </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p1413r3.pdf" target="_top">
        P1413R3
        </a>
      </td><td align="center"> </td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left"> A type trait to detect reference binding to temporary </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2255r2.html" target="_top">
        P2255R2
        </a>
      </td><td align="center"> </td><td align="left"> <code class="code">__cpp_lib_reference_from_temporary &gt;= 202202L</code> </td></tr><tr><td colspan="4" align="left">
        <span class="bold"><strong>Strings and text</strong></span>
      </td></tr><tr><td align="left"> string contains function </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p1679r3.html" target="_top">
        P1679R3
        </a>
      </td><td align="center"> 11.1 </td><td align="left"> <code class="code">__cpp_lib_string_contains &gt;= 202011L</code> </td></tr><tr><td align="left"> Prohibit std::basic_string and std::basic_string_view construction from nullptr </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p2166r1.html" target="_top">
        P2166R1
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> </td></tr><tr><td align="left"> basic_string::resize_and_overwrite </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p1072r10.html" target="_top">
        P1072R10
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_resize_and_overwrite &gt;= 202110L</code> </td></tr><tr><td align="left"> A strstream replacement using span&lt;charT&gt; as buffer </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p0448r4.pdf" target="_top">
        P0448R4
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_spanstream &gt;= 202106L</code> </td></tr><tr><td colspan="4" align="left">
        <span class="bold"><strong>Containers</strong></span>
      </td></tr><tr><td align="left"> Iterator pair constructors for stack and queue </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p1425r4.pdf" target="_top">
        P1425R4
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_adaptor_iterator_pair_constructor &gt;= 202106L</code> </td></tr><tr><td align="left"> Stop overconstraining allocators in container deduction guides </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p1518r2.html" target="_top">
        P1518R2
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left"> Heterogeneous erasure overloads for associative containers </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2077r3.html" target="_top">
        P2077R3
        </a>
      </td><td align="center"> </td><td align="left"> <code class="code">__cpp_lib_associative_heterogeneous_erasure &gt;= 202110L</code> </td></tr><tr><td colspan="4" align="left">
        <span class="bold"><strong>Miscellaneous</strong></span>
      </td></tr><tr><td align="left"> Inheriting from <code class="code">std::variant</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2162r2.html" target="_top">
        P2162R2
        </a>
      </td><td align="center"> 11.3 </td><td align="left"> <code class="code">__cpp_lib_variant &gt;= 202102L</code> </td></tr><tr><td align="left"> Printing <code class="code">volatile</code> Pointers </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p1147r1.html" target="_top">
        P1147R1
        </a>
      </td><td align="center"> 11.3 </td><td align="left"> </td></tr><tr><td align="left"> A Proposal to add stacktrace library </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p0881r7.html" target="_top">
        P0881R7
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_stacktrace &gt;= 202011L</code> </td></tr><tr><td align="left"> Add a pmr alias for std::stacktrace </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2301r1.html" target="_top">
        P2301R1
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> </td></tr><tr><td align="left"> <code class="code">std::expected</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p0323r12.html" target="_top">
        P0323R12
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_expected &gt;= 202202L</code> </td></tr><tr><td align="left"> Monadic operations for std::optional </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p0798r8.html" target="_top">
        P0798R8
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_optional &gt;= 202110L</code> </td></tr><tr><td align="left"> <code class="code">move_only_function</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p0288r9.html" target="_top">
        P0288R9
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_move_only_function &gt;= 202110L</code> </td></tr><tr><td align="left"> <code class="code">invoke_r</code> </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2136r3.html" target="_top">
        P2136R3
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_invoke_r &gt;= 202106L</code> </td></tr><tr><td align="left"> Byteswapping for fun&amp;&amp;nuf </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p1272r4.html" target="_top">
        P1272R4
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_byteswap &gt;= 202110L</code> </td></tr><tr><td align="left"> Function to mark unreachable code </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p0627r6.pdf" target="_top">
        P0627R6
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_unreachable &gt;= 202202L</code> </td></tr><tr><td align="left"> Add a conditional noexcept specification to std::exchange </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2401r0.html" target="_top">
        P2401R0
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> </td></tr><tr><td align="left"> Support C atomics in C++ </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p0943r6.html" target="_top">
        P0943R6
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> <code class="code">__cpp_lib_stdatomic_h &gt;= 202011L</code> </td></tr><tr><td align="left"> Clarifying the status of the "C headers" </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2340r1.html" target="_top">
        P2340R1
        </a>
      </td><td align="center"> Yes </td><td align="left"> </td></tr><tr><td align="left"> Relax Requirements for time_point::clock </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p2212r2.html" target="_top">
        P2212R2
        </a>
      </td><td align="center"> Yes </td><td align="left"> </td></tr><tr><td align="left"> Removing Garbage Collection Support </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2186r2.html" target="_top">
        P2186R2
        </a>
      </td><td align="center"> 12.1 </td><td align="left"> </td></tr><tr><td align="left"> Easy [utilities], [ranges], and [iterators] </td><td align="left">
        <a class="link" href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p1642r11.html" target="_top">
        P1642R11
        </a>
      </td><td align="center"> 13.1 </td><td align="left"> </td></tr></tbody></table></div></div><br class="table-break" /></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="status.iso.tr1"></a>C++ TR1</h3></div></div></div><p>
This table is based on the table of contents of ISO/IEC DTR 19768,
Doc No: N1836=05-0096, Date: 2005-06-24,
"Draft Technical Report on C++ Library Extensions".
</p><p>
In this implementation the header names are prefixed by
<code class="code">tr1/</code>, for instance <code class="code">&lt;tr1/functional&gt;</code>,
<code class="code">&lt;tr1/memory&gt;</code>, and so on.
</p><p>
This page describes the TR1 support in mainline GCC, not in any particular
release.
</p><div class="table"><a id="table.tr1_status"></a><p class="title"><strong>Table 1.11. C++ TR1 Implementation Status</strong></p><div class="table-contents"><table class="table" summary="C++ TR1 Implementation Status" border="1"><colgroup><col align="left" class="c1" /><col align="left" class="c2" /><col align="left" class="c3" /><col align="left" class="c4" /></colgroup><thead><tr><th align="left">Section</th><th align="left">Description</th><th align="left">Status</th><th align="left">Comments</th></tr></thead><tbody><tr><td align="left"><span class="emphasis"><em>2</em></span></td><td colspan="3" align="left"><span class="emphasis"><em>General Utilities</em></span></td></tr><tr><td align="left">2.1</td><td align="left">Reference wrappers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">2.1.1</td><td align="left">Additions to header <code class="code">&lt;functional&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.1.2</td><td align="left">Class template <code class="code">reference_wrapper</code></td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">2.1.2.1</td><td align="left"><code class="code">reference_wrapper</code> construct/copy/destroy</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.1.2.2</td><td align="left"><code class="code">reference_wrapper</code> assignment</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.1.2.3</td><td align="left"><code class="code">reference_wrapper</code> access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.1.2.4</td><td align="left"><code class="code">reference_wrapper</code> invocation</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.1.2.5</td><td align="left"><code class="code">reference_wrapper</code> helper functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2</td><td align="left">Smart pointers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">2.2.1</td><td align="left">Additions to header <code class="code">&lt;memory&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.2</td><td align="left">Class <code class="code">bad_weak_ptr</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.3</td><td align="left">Class template <code class="code">shared_ptr</code></td><td align="left"> </td><td align="left">
	<p>
	  Uses code from
	  <a class="link" href="http://www.boost.org/libs/smart_ptr/shared_ptr.htm" target="_top">boost::shared_ptr</a>.
	</p>
      </td></tr><tr><td align="left">2.2.3.1</td><td align="left"><code class="code">shared_ptr</code> constructors</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.3.2</td><td align="left"><code class="code">shared_ptr</code> destructor</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.3.3</td><td align="left"><code class="code">shared_ptr</code> assignment</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.3.4</td><td align="left"><code class="code">shared_ptr</code> modifiers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.3.5</td><td align="left"><code class="code">shared_ptr</code> observers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.3.6</td><td align="left"><code class="code">shared_ptr</code> comparison</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.3.7</td><td align="left"><code class="code">shared_ptr</code> I/O</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.3.8</td><td align="left"><code class="code">shared_ptr</code> specialized algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.3.9</td><td align="left"><code class="code">shared_ptr</code> casts</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.3.10</td><td align="left"><code class="code">get_deleter</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.4</td><td align="left">Class template <code class="code">weak_ptr</code></td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">2.2.4.1</td><td align="left"><code class="code">weak_ptr</code> constructors</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.4.2</td><td align="left"><code class="code">weak_ptr</code> destructor</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.4.3</td><td align="left"><code class="code">weak_ptr</code> assignment</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.4.4</td><td align="left"><code class="code">weak_ptr</code> modifiers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.4.5</td><td align="left"><code class="code">weak_ptr</code> observers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.4.6</td><td align="left"><code class="code">weak_ptr</code> comparison</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.4.7</td><td align="left"><code class="code">weak_ptr</code> specialized algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">2.2.5</td><td align="left">Class template <code class="code">enable_shared_from_this</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left"><span class="emphasis"><em>3</em></span></td><td colspan="3" align="left"><span class="emphasis"><em>Function Objects</em></span></td></tr><tr><td align="left">3.1</td><td align="left">Definitions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.2</td><td align="left">Additions to <code class="code">&lt;functional&gt; synopsis</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.3</td><td align="left">Requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.4</td><td align="left">Function return types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.5</td><td align="left">Function template <code class="code">mem_fn</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.6</td><td align="left">Function object binders</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">3.6.1</td><td align="left">Class template <code class="code">is_bind_expression</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.6.2</td><td align="left">Class template <code class="code">is_placeholder</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.6.3</td><td align="left">Function template <code class="code">bind</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.6.4</td><td align="left">Placeholders</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.7</td><td align="left">Polymorphic function wrappers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">3.7.1</td><td align="left">Class <code class="code">bad_function_call</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.7.1.1</td><td align="left"><code class="code">bad_function_call</code> constructor</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.7.2</td><td align="left">Class template <code class="code">function</code></td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">3.7.2.1</td><td align="left"><code class="code">function</code> construct/copy/destroy</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.7.2.2</td><td align="left"><code class="code">function</code> modifiers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.7.2.3</td><td align="left"><code class="code">function</code> capacity</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.7.2.4</td><td align="left"><code class="code">function</code> invocation</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.7.2.5</td><td align="left"><code class="code">function</code> target access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.7.2.6</td><td align="left">undefined operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.7.2.7</td><td align="left">null pointer comparison operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.7.2.8</td><td align="left">specialized algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left"><span class="emphasis"><em>4</em></span></td><td colspan="3" align="left"><span class="emphasis"><em>Metaprogramming and type traits</em></span></td></tr><tr><td align="left">4.1</td><td align="left">Requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">4.2</td><td align="left">Header <code class="code">&lt;type_traits&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">4.3</td><td align="left">Helper classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">4.4</td><td align="left">General Requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">4.5</td><td align="left">Unary Type Traits</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">4.5.1</td><td align="left">Primary Type Categories</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">4.5.2</td><td align="left">Composite type traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">4.5.3</td><td align="left">Type properties</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">4.6</td><td align="left">Relationships between types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">4.7</td><td align="left">Transformations between types</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">4.7.1</td><td align="left">Const-volatile modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">4.7.2</td><td align="left">Reference modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">4.7.3</td><td align="left">Array modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">4.7.4</td><td align="left">Pointer modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">4.8</td><td align="left">Other transformations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">4.9</td><td align="left">Implementation requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left"><span class="emphasis"><em>5</em></span></td><td colspan="3" align="left"><span class="emphasis"><em>Numerical Facilities</em></span></td></tr><tr><td align="left">5.1</td><td align="left">Random number generation</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">5.1.1</td><td align="left">Requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.2</td><td align="left">Header <code class="code">&lt;random&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.3</td><td align="left">Class template <code class="code">variate_generator</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.4</td><td align="left">Random number engine class templates</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.4.1</td><td align="left">Class template <code class="code">linear_congruential</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.4.2</td><td align="left">Class template <code class="code">mersenne_twister</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.4.3</td><td align="left">Class template <code class="code">subtract_with_carry</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.4.4</td><td align="left">Class template <code class="code">subtract_with_carry_01</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.4.5</td><td align="left">Class template <code class="code">discard_block</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.4.6</td><td align="left">Class template <code class="code">xor_combine</code></td><td align="left">Y</td><td align="left">operator()() per N2079</td></tr><tr><td align="left">5.1.5</td><td align="left">Engines with predefined parameters</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.6</td><td align="left">Class <code class="code">random_device</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.7</td><td align="left">Random distribution class templates</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.7.1</td><td align="left">Class template <code class="code">uniform_int</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.7.2</td><td align="left">Class <code class="code">bernoulli_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.7.3</td><td align="left">Class template <code class="code">geometric_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.7.4</td><td align="left">Class template <code class="code">poisson_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.7.5</td><td align="left">Class template <code class="code">binomial_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.7.6</td><td align="left">Class template <code class="code">uniform_real</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.7.7</td><td align="left">Class template <code class="code">exponential_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.7.8</td><td align="left">Class template <code class="code">normal_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.1.7.9</td><td align="left">Class template <code class="code">gamma_distribution</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2</td><td align="left">Mathematical special functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1</td><td align="left">Additions to header <code class="code">&lt;cmath&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.1</td><td align="left">associated Laguerre polynomials</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.2</td><td align="left">associated Legendre functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.3</td><td align="left">beta function</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.4</td><td align="left">(complete) elliptic integral of the first kind</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.5</td><td align="left">(complete) elliptic integral of the second kind</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.6</td><td align="left">(complete) elliptic integral of the third kind</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.7</td><td align="left">confluent hypergeometric functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.8</td><td align="left">regular modified cylindrical Bessel functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.9</td><td align="left">cylindrical Bessel functions (of the first kind)</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.10</td><td align="left">irregular modified cylindrical Bessel functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.11</td><td align="left">cylindrical Neumann functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.12</td><td align="left">(incomplete) elliptic integral of the first kind</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.13</td><td align="left">(incomplete) elliptic integral of the second kind</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.14</td><td align="left">(incomplete) elliptic integral of the third kind</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.15</td><td align="left">exponential integral</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.16</td><td align="left">Hermite polynomials</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.17</td><td align="left">hypergeometric functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.18</td><td align="left">Laguerre polynomials</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.19</td><td align="left">Legendre polynomials</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.20</td><td align="left">Riemann zeta function</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.21</td><td align="left">spherical Bessel functions (of the first kind)</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.22</td><td align="left">spherical associated Legendre functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.1.23</td><td align="left">spherical Neumann functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">5.2.2</td><td align="left">Additions to header <code class="code">&lt;math.h&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left"><span class="emphasis"><em>6</em></span></td><td colspan="3" align="left"><span class="emphasis"><em>Containers</em></span></td></tr><tr><td align="left">6.1</td><td align="left">Tuple types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.1.1</td><td align="left">Header <code class="code">&lt;tuple&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.1.2</td><td align="left">Additions to header <code class="code">&lt;utility&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.1.3</td><td align="left">Class template <code class="code">tuple</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.1.3.1</td><td align="left">Construction</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.1.3.2</td><td align="left">Tuple creation functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.1.3.3</td><td align="left">Tuple helper classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.1.3.4</td><td align="left">Element access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.1.3.5</td><td align="left">Relational operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.1.4</td><td align="left">Pairs</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.2</td><td align="left">Fixed size array</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.2.1</td><td align="left">Header <code class="code">&lt;array&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.2.2</td><td align="left">Class template <code class="code">array</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.2.2.1</td><td align="left"><code class="code">array</code> constructors, copy, and assignment</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.2.2.2</td><td align="left"><code class="code">array</code> specialized algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.2.2.3</td><td align="left"><code class="code">array</code> size</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.2.2.4</td><td align="left">Zero sized <code class="code">array</code>s</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.2.2.5</td><td align="left">Tuple interface to class template <code class="code">array</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3</td><td align="left">Unordered associative containers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.1</td><td align="left">Unordered associative container requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.1.1</td><td align="left">Exception safety guarantees</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.2</td><td align="left">Additions to header <code class="code">&lt;functional&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.3</td><td align="left">Class template <code class="code">hash</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.4</td><td align="left">Unordered associative container classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.4.1</td><td align="left">Header <code class="code">&lt;unordered_set&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.4.2</td><td align="left">Header <code class="code">&lt;unordered_map&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.4.3</td><td align="left">Class template <code class="code">unordered_set</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.4.3.1</td><td align="left"><code class="code">unordered_set</code> constructors</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.4.3.2</td><td align="left"><code class="code">unordered_set</code> swap</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.4.4</td><td align="left">Class template <code class="code">unordered_map</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.4.4.1</td><td align="left"><code class="code">unordered_map</code> constructors</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.4.4.2</td><td align="left"><code class="code">unordered_map</code> element access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.4.4.3</td><td align="left"><code class="code">unordered_map</code> swap</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.4.5</td><td align="left">Class template <code class="code">unordered_multiset</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.4.5.1</td><td align="left"><code class="code">unordered_multiset</code> constructors</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.4.5.2</td><td align="left"><code class="code">unordered_multiset</code> swap</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.4.6</td><td align="left">Class template <code class="code">unordered_multimap</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.4.6.1</td><td align="left"><code class="code">unordered_multimap</code> constructors</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">6.3.4.6.2</td><td align="left"><code class="code">unordered_multimap</code> swap</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left"><span class="emphasis"><em>7</em></span></td><td colspan="3" align="left"><span class="emphasis"><em>Regular Expressions</em></span></td></tr><tr bgcolor="#C8B0B0"><td align="left">7.1</td><td align="left">Definitions</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.2</td><td align="left">Requirements</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.3</td><td align="left">Regular expressions summary</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.4</td><td align="left">Header <code class="code">&lt;regex&gt;</code> synopsis</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.5</td><td align="left">Namespace <code class="code">tr1::regex_constants</code></td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.5.1</td><td align="left">Bitmask Type <code class="code">syntax_option_type</code></td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.5.2</td><td align="left">Bitmask Type <code class="code">regex_constants::match_flag_type</code></td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.5.3</td><td align="left">Implementation defined <code class="code">error_type</code></td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.6</td><td align="left">Class <code class="code">regex_error</code></td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.7</td><td align="left">Class template <code class="code">regex_traits</code></td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.8</td><td align="left">Class template <code class="code">basic_regex</code></td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.8.1</td><td align="left"><code class="code">basic_regex</code> constants</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.8.2</td><td align="left"><code class="code">basic_regex</code> constructors</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.8.3</td><td align="left"><code class="code">basic_regex</code> assign</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.8.4</td><td align="left"><code class="code">basic_regex</code> constant operations</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.8.5</td><td align="left"><code class="code">basic_regex</code> locale</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.8.6</td><td align="left"><code class="code">basic_regex</code> swap</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.8.7</td><td align="left"><code class="code">basic_regex</code> non-member functions</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.8.7.1</td><td align="left"><code class="code">basic_regex</code> non-member swap</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.9</td><td align="left">Class template <code class="code">sub_match</code></td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.9.1</td><td align="left"><code class="code">sub_match</code> members</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.9.2</td><td align="left"><code class="code">sub_match</code> non-member operators</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.10</td><td align="left">Class template <code class="code">match_results</code></td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.10.1</td><td align="left"><code class="code">match_results</code> constructors</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.10.2</td><td align="left"><code class="code">match_results</code> size</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.10.3</td><td align="left"><code class="code">match_results</code> element access</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.10.4</td><td align="left"><code class="code">match_results</code> formatting</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.10.5</td><td align="left"><code class="code">match_results</code> allocator</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.10.6</td><td align="left"><code class="code">match_results</code> swap</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.11</td><td align="left">Regular expression algorithms</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.11.1</td><td align="left">exceptions</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.11.2</td><td align="left"><code class="code">regex_match</code></td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.11.3</td><td align="left"><code class="code">regex_search</code></td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.11.4</td><td align="left"><code class="code">regex_replace</code></td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.12</td><td align="left">Regular expression Iterators</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.12.1</td><td align="left">Class template <code class="code">regex_iterator</code></td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.12.1.1</td><td align="left"><code class="code">regex_iterator</code> constructors</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.12.1.2</td><td align="left"><code class="code">regex_iterator</code> comparisons</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.12.1.3</td><td align="left"><code class="code">regex_iterator</code> dereference</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.12.1.4</td><td align="left"><code class="code">regex_iterator</code> increment</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.12.2</td><td align="left">Class template <code class="code">regex_token_iterator</code></td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.12.2.1</td><td align="left"><code class="code">regex_token_iterator</code> constructors</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.12.2.2</td><td align="left"><code class="code">regex_token_iterator</code> comparisons</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.12.2.3</td><td align="left"><code class="code">regex_token_iterator</code> dereference</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.12.2.4</td><td align="left"><code class="code">regex_token_iterator</code> increment</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">7.13</td><td align="left">Modified ECMAScript regular expression grammar</td><td align="left">N</td><td align="left"> </td></tr><tr><td align="left"><span class="emphasis"><em>8</em></span></td><td colspan="3" align="left"><span class="emphasis"><em>C Compatibility</em></span></td></tr><tr><td align="left">8.1</td><td align="left">Additions to header <code class="code">&lt;complex&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.1</td><td align="left">Synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.2</td><td align="left">Function <code class="code">acos</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.3</td><td align="left">Function <code class="code">asin</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.4</td><td align="left">Function <code class="code">atan</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.5</td><td align="left">Function <code class="code">acosh</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.6</td><td align="left">Function <code class="code">asinh</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.7</td><td align="left">Function <code class="code">atanh</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.8</td><td align="left">Function <code class="code">fabs</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.9</td><td align="left">Additional Overloads</td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">8.2</td><td align="left">Header <code class="code">&lt;ccomplex&gt;</code></td><td align="left">N</td><td align="left">DR 551</td></tr><tr bgcolor="#C8B0B0"><td align="left">8.3</td><td align="left">Header <code class="code">&lt;complex.h&gt;</code></td><td align="left">N</td><td align="left">DR 551</td></tr><tr><td align="left">8.4</td><td align="left">Additions to header <code class="code">&lt;cctype&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.4.1</td><td align="left">Synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.4.2</td><td align="left">Function <code class="code">isblank</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.5</td><td align="left">Additions to header <code class="code">&lt;ctype.h&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.6</td><td align="left">Header <code class="code">&lt;cfenv&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.6.1</td><td align="left">Synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.6.2</td><td align="left">Definitions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.7</td><td align="left">Header <code class="code">&lt;fenv.h&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.8</td><td align="left">Additions to header <code class="code">&lt;cfloat&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.9</td><td align="left">Additions to header <code class="code">&lt;float.h&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">8.10</td><td align="left">Additions to header <code class="code">&lt;ios&gt;</code></td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">8.10.1</td><td align="left">Synopsis</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">8.10.2</td><td align="left">Function <code class="code">hexfloat</code></td><td align="left">N</td><td align="left"> </td></tr><tr><td align="left">8.11</td><td align="left">Header <code class="code">&lt;cinttypes&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.11.1</td><td align="left">Synopsis</td><td align="left">Y</td><td align="left">DR 557</td></tr><tr><td align="left">8.11.2</td><td align="left">Definitions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.12</td><td align="left">Header <code class="code">&lt;inttypes.h&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.13</td><td align="left">Additions to header <code class="code">&lt;climits&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.14</td><td align="left">Additions to header <code class="code">&lt;limits.h&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">8.15</td><td align="left">Additions to header <code class="code">&lt;locale&gt;</code></td><td align="left">N</td><td align="left"> </td></tr><tr><td align="left">8.16</td><td align="left">Additions to header <code class="code">&lt;cmath&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.16.1</td><td align="left">Synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.16.2</td><td align="left">Definitions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.16.3</td><td align="left">Function template definitions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.16.4</td><td align="left">Additional overloads</td><td align="left">Y</td><td align="left">DR 568; DR 550</td></tr><tr><td align="left">8.17</td><td align="left">Additions to header <code class="code">&lt;math.h&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.18</td><td align="left">Additions to header <code class="code">&lt;cstdarg&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.19</td><td align="left">Additions to header <code class="code">&lt;stdarg.h&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.20</td><td align="left">The header <code class="code">&lt;cstdbool&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.21</td><td align="left">The header <code class="code">&lt;stdbool.h&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.22</td><td align="left">The header <code class="code">&lt;cstdint&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.22.1</td><td align="left">Synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.22.2</td><td align="left">Definitions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.23</td><td align="left">The header <code class="code">&lt;stdint.h&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.24</td><td align="left">Additions to header <code class="code">&lt;cstdio&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.24.1</td><td align="left">Synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.24.2</td><td align="left">Definitions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.24.3</td><td align="left">Additional format specifiers</td><td align="left">Y</td><td align="left">C library dependency</td></tr><tr><td align="left">8.24.4</td><td align="left">Additions to header <code class="code">&lt;stdio.h&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.25</td><td align="left">Additions to header <code class="code">&lt;cstdlib&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.25.1</td><td align="left">Synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.25.2</td><td align="left">Definitions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.25.3</td><td align="left">Function <code class="code">abs</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.25.4</td><td align="left">Function <code class="code">div</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.26</td><td align="left">Additions to header <code class="code">&lt;stdlib.h&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.27</td><td align="left">Header <code class="code">&lt;ctgmath&gt;</code></td><td align="left">Y</td><td align="left">DR 551</td></tr><tr><td align="left">8.28</td><td align="left">Header <code class="code">&lt;tgmath.h&gt;</code></td><td align="left">Y</td><td align="left">DR 551</td></tr><tr><td align="left">8.29</td><td align="left">Additions to header <code class="code">&lt;ctime&gt;</code></td><td align="left">Y</td><td align="left">C library dependency</td></tr><tr><td align="left">8.30</td><td align="left">Additions to header <code class="code">&lt;cwchar&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.30.1</td><td align="left">Synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.30.2</td><td align="left">Definitions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.30.3</td><td align="left">Additional wide format specifiers</td><td align="left">Y</td><td align="left">C library dependency</td></tr><tr><td align="left">8.31</td><td align="left">Additions to header <code class="code">&lt;wchar.h&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.32</td><td align="left">Additions to header <code class="code">&lt;cwctype&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.32.1</td><td align="left">Synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.32.2</td><td align="left">Function <code class="code">iswblank</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.33</td><td align="left">Additions to header <code class="code">&lt;wctype.h&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr></tbody></table></div></div><br class="table-break" /><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="iso.tr1.specific"></a>Implementation Specific Behavior</h4></div></div></div><p>For behaviour which is specified by the 1998 and 2003 standards,
      see <a class="link" href="status.html#iso.1998.specific" title="Implementation Specific Behavior">C++ 1998/2003 Implementation
      Specific Behavior</a>. This section documents behaviour which
      is required by TR1.
   </p><p>
     <span class="emphasis"><em>3.6.4 [tr.func.bind.place]/1</em></span> There are 29
     placeholders defined and the placeholder types are
     <code class="literal">Assignable</code>.
   </p></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="status.iso.tr24733"></a>C++ TR 24733</h3></div></div></div><p>
This table is based on the table of contents of
ISO/IEC TR 24733:2011,
"Extensions for the programming language C++ to support
decimal floating-point arithmetic".
</p><p>
This page describes the TR 24733 support in mainline GCC, not in any
particular release.
</p><div class="table"><a id="table.decfp_status"></a><p class="title"><strong>Table 1.12. C++ TR 24733 Implementation Status</strong></p><div class="table-contents"><table class="table" summary="C++ TR 24733 Implementation Status" border="1"><colgroup><col align="left" class="c1" /><col align="left" class="c2" /><col align="left" class="c3" /><col align="left" class="c4" /></colgroup><thead><tr><th align="left">Section</th><th align="left">Description</th><th align="left">Status</th><th align="left">Comments</th></tr></thead><tbody><tr><td align="left">
	<span class="emphasis"><em>0</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Introduction</em></span>
      </td></tr><tr><td align="left">
	<span class="emphasis"><em>1</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Normative references</em></span>
      </td></tr><tr><td align="left">
	<span class="emphasis"><em>2</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Conventions</em></span>
      </td></tr><tr><td align="left">
	<span class="emphasis"><em>3</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Decimal floating-point types</em></span>
      </td></tr><tr><td align="left">3.1</td><td align="left">Characteristics of decimal floating-point types</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">3.2</td><td align="left">Decimal Types</td><td align="left"> </td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">3.2.1</td><td align="left">Class <code class="code">decimal</code> synopsis</td><td align="left">Partial</td><td align="left">Missing declarations for formatted input/output; non-conforming extension for functions converting to integral type</td></tr><tr bgcolor="#B0B0B0"><td align="left">3.2.2</td><td align="left">Class <code class="code">decimal32</code></td><td align="left">Partial</td><td align="left">Missing 3.2.2.5 conversion to integral type; conforming extension for conversion from scalar decimal floating-point</td></tr><tr bgcolor="#B0B0B0"><td align="left">3.2.3</td><td align="left">Class <code class="code">decimal64</code></td><td align="left">Partial</td><td align="left">Missing 3.2.3.5 conversion to integral type; conforming extension for conversion from scalar decimal floating-point</td></tr><tr bgcolor="#B0B0B0"><td align="left">3.2.4</td><td align="left">Class <code class="code">decimal128</code></td><td align="left">Partial</td><td align="left">Missing 3.2.4.5 conversion to integral type; conforming extension for conversion from scalar decimal floating-point</td></tr><tr><td align="left">3.2.5</td><td align="left">Initialization from coefficient and exponent</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.2.6</td><td align="left">Conversion to generic floating-point type</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.2.7</td><td align="left">Unary arithmetic operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.2.8</td><td align="left">Binary arithmetic operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.2.9</td><td align="left">Comparison operators</td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">3.2.10</td><td align="left">Formatted input</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">3.2.11</td><td align="left">Formatted output</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">3.3</td><td align="left">Additions to header <code class="code">limits</code></td><td align="left">N</td><td align="left"> </td></tr><tr><td align="left">3.4</td><td align="left">Headers <code class="code">cfloat</code> and <code class="code">float.h</code></td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">3.4.2</td><td align="left">Additions to header <code class="code">cfloat</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">3.4.3</td><td align="left">Additions to header <code class="code">float.h</code> synopsis</td><td align="left">N</td><td align="left"> </td></tr><tr><td align="left">3.4.4</td><td align="left">Maximum finite value</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.4.5</td><td align="left">Epsilon</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.4.6</td><td align="left">Minimum positive normal value</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.4.7</td><td align="left">Minimum positive subnormal value</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">3.4.8</td><td align="left">Evaluation format</td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">3.5</td><td align="left">Additions to <code class="code">cfenv</code> and <code class="code">fenv.h</code></td><td align="left">Outside the scope of GCC</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">3.6</td><td align="left">Additions to <code class="code">cmath</code> and <code class="code">math.h</code></td><td align="left">Outside the scope of GCC</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">3.7</td><td align="left">Additions to <code class="code">cstdio</code> and <code class="code">stdio.h</code></td><td align="left">Outside the scope of GCC</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">3.8</td><td align="left">Additions to <code class="code">cstdlib</code> and <code class="code">stdlib.h</code></td><td align="left">Outside the scope of GCC</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">3.9</td><td align="left">Additions to <code class="code">cwchar</code> and <code class="code">wchar.h</code></td><td align="left">Outside the scope of GCC</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">3.10</td><td align="left">Facets</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">3.11</td><td align="left">Type traits</td><td align="left">N</td><td align="left"> </td></tr><tr bgcolor="#C8B0B0"><td align="left">3.12</td><td align="left">Hash functions</td><td align="left">N</td><td align="left"> </td></tr><tr><td align="left">
	<span class="emphasis"><em>4</em></span>
      </td><td colspan="3" align="left">
	<span class="emphasis"><em>Notes on C compatibility</em></span>
      </td></tr></tbody></table></div></div><br class="table-break" /></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="status.iso.specfun"></a>C++ IS 29124</h3></div></div></div><p>
This table is based on the table of contents of ISO/IEC FDIS 29124,
Doc No: N3060, Date: 2010-03-06,
"Extensions to the C++ Library to support mathematical special functions".
</p><p>
Complete support for IS 29124 is in GCC 6.1 and later releases, when using
at least C++11 (for older releases or C++98/C++03 use TR1 instead).
For C++11 and C++14 the additions to the library are not declared by their
respective headers unless <code class="code">__STDCPP_WANT_MATH_SPEC_FUNCS__</code>
is defined as a macro that expands to a non-zero integer constant.
For C++17 the special functions are always declared (since GCC 7.1).
</p><p>
When the special functions are declared the macro
<code class="code">__STDCPP_MATH_SPEC_FUNCS__</code> is defined to <code class="code">201003L</code>.
</p><p>
In addition to the special functions defined in IS 29124, for
non-strict modes (i.e. <code class="code">-std=gnu++NN</code> modes) the
hypergeometric functions and confluent hypergeometric functions
from TR1 are also provided, defined in namespace
<code class="code">__gnu_cxx</code>.
</p><div class="table"><a id="table.specfun_status"></a><p class="title"><strong>Table 1.13. C++ Special Functions Implementation Status</strong></p><div class="table-contents"><table class="table" summary="C++ Special Functions Implementation Status" border="1"><colgroup><col align="left" class="c1" /><col align="left" class="c2" /><col align="left" class="c3" /><col align="left" class="c4" /></colgroup><thead><tr><th align="left">Section</th><th align="left">Description</th><th align="left">Status</th><th align="left">Comments</th></tr></thead><tbody><tr bgcolor="#B0B0B0"><td align="left">7</td><td align="left">Macro names</td><td align="left">Partial</td><td align="left">No diagnostic for inconsistent definitions of
             <code class="code">__STDCPP_WANT_MATH_SPEC_FUNCS__</code></td></tr><tr><td align="left">8</td><td align="left">Mathematical special functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1</td><td align="left">Additions to header <code class="code">&lt;cmath&gt;</code> synopsis</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.1</td><td align="left">associated Laguerre polynomials</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.2</td><td align="left">associated Legendre functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.3</td><td align="left">beta function</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.4</td><td align="left">(complete) elliptic integral of the first kind</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.5</td><td align="left">(complete) elliptic integral of the second kind</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.6</td><td align="left">(complete) elliptic integral of the third kind</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.7</td><td align="left">regular modified cylindrical Bessel functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.8</td><td align="left">cylindrical Bessel functions (of the first kind)</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.9</td><td align="left">irregular modified cylindrical Bessel functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.10</td><td align="left">cylindrical Neumann functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.11</td><td align="left">(incomplete) elliptic integral of the first kind</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.12</td><td align="left">(incomplete) elliptic integral of the second kind</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.13</td><td align="left">(incomplete) elliptic integral of the third kind</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.14</td><td align="left">exponential integral</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.15</td><td align="left">Hermite polynomials</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.16</td><td align="left">Laguerre polynomials</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.17</td><td align="left">Legendre polynomials</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.18</td><td align="left">Riemann zeta function</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.19</td><td align="left">spherical Bessel functions (of the first kind)</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.20</td><td align="left">spherical associated Legendre functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.1.21</td><td align="left">spherical Neumann functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">8.2</td><td align="left">Additions to header <code class="code">&lt;math.h&gt;</code></td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">8.3</td><td align="left">The header <code class="code">&lt;ctgmath&gt;</code></td><td align="left">Partial</td><td align="left">Conflicts with C++ 2011 requirements.</td></tr><tr bgcolor="#C8B0B0"><td align="left">8.4</td><td align="left">The header <code class="code">&lt;tgmath.h&gt;</code></td><td align="left">N</td><td align="left">Conflicts with C++ 2011 requirements.</td></tr></tbody></table></div></div><br class="table-break" /><div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="iso.specfun.specific"></a>Implementation Specific Behavior</h4></div></div></div><p>For behaviour which is specified by the 2011 standard,
      see <a class="link" href="status.html#iso.2011.specific" title="Implementation Specific Behavior">C++ 2011 Implementation
      Specific Behavior</a>. This section documents behaviour which
      is required by IS 29124.
   </p><p>
     <span class="emphasis"><em>7.2 [macro.user]/3 /4</em></span> The functions declared in
     Clause 8 are only declared when
     <code class="code">__STDCPP_WANT_MATH_SPEC_FUNCS__ == 1</code>
     (or in C++17 mode, for GCC 7.1 and later).
   </p><p>
     <span class="emphasis"><em>8.1.1 [sf.cmath.Lnm]/1</em></span> The effect of calling
     these functions with <code class="code">n &gt;= 128</code> or <code class="code">m &gt;= 128</code>
     should be described here.
   </p><p>
     <span class="emphasis"><em>8.1.2 [sf.cmath.Plm]/3</em></span> The effect of calling
     these functions with <code class="code">l &gt;= 128</code> should be described here.
   </p><p>
     <span class="emphasis"><em>8.1.3 [sf.cmath.I]/3</em></span> The effect of calling
     these functions with <code class="code">nu &gt;= 128</code> should be described here.
   </p><p>
     <span class="emphasis"><em>8.1.8 [sf.cmath.J]/3</em></span> The effect of calling
     these functions with <code class="code">nu &gt;= 128</code> should be described here.
   </p><p>
     <span class="emphasis"><em>8.1.9 [sf.cmath.K]/3</em></span> The effect of calling
     these functions with <code class="code">nu &gt;= 128</code> should be described here.
   </p><p>
     <span class="emphasis"><em>8.1.10 [sf.cmath.N]/3</em></span> The effect of calling
     these functions with <code class="code">nu &gt;= 128</code> should be described here.
   </p><p>
     <span class="emphasis"><em>8.1.15 [sf.cmath.Hn]/3</em></span> The effect of calling
     these functions with <code class="code">n &gt;= 128</code> should be described here.
   </p><p>
     <span class="emphasis"><em>8.1.16 [sf.cmath.Ln]/3</em></span> The effect of calling
     these functions with <code class="code">n &gt;= 128</code> should be described here.
   </p><p>
     <span class="emphasis"><em>8.1.17 [sf.cmath.Pl]/3</em></span> The effect of calling
     these functions with <code class="code">l &gt;= 128</code> should be described here.
   </p><p>
     <span class="emphasis"><em>8.1.19 [sf.cmath.j]/3</em></span> The effect of calling
     these functions with <code class="code">n &gt;= 128</code> should be described here.
   </p><p>
     <span class="emphasis"><em>8.1.20 [sf.cmath.Ylm]/3</em></span> The effect of calling
     these functions with <code class="code">l &gt;= 128</code> should be described here.
   </p><p>
     <span class="emphasis"><em>8.1.21 [sf.cmath.n]/3</em></span> The effect of calling
     these functions with <code class="code">n &gt;= 128</code> should be described here.
   </p></div></div></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="intro.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="intro.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="license.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Part I. 
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